Deep-Sea Research II 111 (2015) 301–324 Contents lists available at ScienceDirect Deep-Sea Research II journal homepage: www.elsevier.com/locate/dsr2 Three new species and one new genus of abyssal Cumacea (Crustacea, Malacostraca, Peracarida) from the Kuril–Kamchatka Trench area Anna V. Lavrenteva a,n, Ute Mühlenhardt-Siegel b a b A.V. Zhirmunsky Institute of Marine Biology, Far Eastern Branch of the Russian Academy of Sciences, 17 Palchevsky St, 690041 Vladivostok, Russia Biocentre Grindel and Zoological Museum, University of Hamburg, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany art ic l e i nf o a b s t r a c t Available online 27 August 2014 Only two species of crustacean Cumacea have been reported in publications for the Kuril–Kamchatka Trench area after nine expeditions on board of the RV “Vityaz”. During the KuramBio expedition 2012 to the Kuril–Kamchatka Trench and the adjacent abyssal plain at depths 4830–5780 m no less than 72 species of cumaceans from 23 genera and 6 families were sampled. Five genera were recorded for the first time in the studied region: the genera Pseudoleptostyloides and Platycuma were detected for the first time for the Pacific Ocean; Cyclaspoides, Bathylamprops and Styloptocuma were firstly sampled in North Pacific. About 90% of the sampled species appear to be new to science. Three new deep-sea cumacean species and one new genus from the Kurile Kamchatka area are described in the present paper: Abyssoleucon tzarevae gen. n., sp. n. belonging to the family Leuconidae, Cyclaspoides borisovetsi sp. n. and Bathycuma sonne sp. n. of the family Bodotriidae. A distribution map for the species of the genus Cyclaspoides is provided. & 2014 Elsevier Ltd. All rights reserved. Keywords: North pacific Kuril–Kamchatka Trench Deep sea Taxonomy Cumacea New species New genus 1. Introduction The Kurile Kamchatka area has been investigated in the last century during nine expeditions on board the RV “Vityaz” in 1949, 1953–1955, 1957 and 1966. The fauna found in this area has been described in many publications, however the order Cumacea Krøyer, 1846 was little studied and only two species were described and mentioned for the Kuril–Kamchatka Trench area: Makrokylindrus vitiasi Lomakina, 1958 (2840 m) and Vaunthompsonia aff. cristata Bate, 1858 (6475–6571 m) (Belyaev, 1989; Lomakina, 1958) and no one cumacean specimen was recorded from depths sampled during the KuramBio expedition. However, these two species were not all cumaceans collected during the Vityaz expeditions – several samples still remain unsorted in the museum of Zoological Institute RAS (St. Petersburg). The German–Russian deep-sea expedition KuramBio (Kurile Kamchatka Biodiversity Studies) on board of RV “Sonne” in the Kuril–Kamchatka Trench area, which sampled in depths between 4830 and 5780 m, has brought an extensive collection of Cumacea. Preliminary identification revealed no less than 72 species from 23 genera and 6 families. Almost 90% of the sampled species seem to be new to science. Five genera are recorded the first time for the studied area: Platycuma Calman, 1905 and a new genus n Corresponding author. E-mail address: AVLavrenteva@yandex.ru (A.V. Lavrenteva). http://dx.doi.org/10.1016/j.dsr2.2014.08.013 0967-0645/& 2014 Elsevier Ltd. All rights reserved. Pseudoleptostyloides of the family Diastylidae from the Atlantic (Mühlenhardt-Siegel) were firstly found in the Pacific Ocean; the genera Cyclaspoides Bonnier, 1896, Bathylamprops Zimmer, 1908 and Styloptocuma Bacescu and Muradian, 1974 were firstly sampled in the North Pacific (Lavrenteva, unpublished data). Cumaceans are usually more frequently occurring and more speciose in the deep sea than on the shelf (Brandt and Piepenburg, 1994) and a preliminary list of the KuramBio species includes almost twice more species than are known for the littoral and bathyal depths of the Kuril and Commander Islands region (Sirenko, 2013). In the KuramBio material the family Leuconidae Sars, 1878 is the most abundant (10 species, 583 specimens; genera: Leucon Krøyer, 1846-7 species; Eudorella Norman, 1867 – species complex; Abyssoleucon gen. n. and Bytholeucon Watling, 1991 are presented by single species). Abyssoleucon tzarevae gen. n., sp. n. is the dominant species within the order Cumacea in the present collection, but it is not a widely distributed species, and was found only at two stations on the western slope of the Kuril–Kamchatka Trench. The Nannastacidae Bate, 1866 (20 species, 396 specimens) and Diastylidae Bate, 1856 (20 species, 337 specimens) are the most speciose families in the present collection. The Nannastacidae includes the following genera: Campylaspis G.O. Sars, 1865, 13 species; Styloptocuma Bacescu and Muradian, 1974, 4 species; Procampylaspis Bonnier, 1896 and Platycuma Calman, 1905 (presented by a single species) and one species with unclear generic position (probably of a new genus). The family Diastylidae is represented by 5 genera: Makrokylindrus Stebbing, 1912 – with 9 species, Diastylis Say, 1818 – with 5 species, and Pseudoleptostyloides, 302 A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Leptostylis G.O. Sars, 1869, Leptostyloides Jones, 1969 – each represented by two species. Family Lampropidae Sars, 1878 is represented by 152 specimens, 12 species and 6 genera: Hemilamprops G.O. Sars, 1883 – with 5 species, Platysympus Stebbing, 1912 – with 2 species, Mesolamprops Given, 1964, Paralamprops Sars, 1887, Bathylamprops Zimmer, 1908, Lamprops (?) G.O. Sars, 1863 – all represented by a single species and one species with unclear generic position. The family Bodotriidae T. Scott, 1901 is represented by 141 specimens, 9 species and 3 genera: 7 species of the genus Bathycuma Hansen, 1895, each of the genera Atlantocuma Bacescu and Muradian, 1974 and Cyclaspoides Bonnier, 1896, are represented by a single species. Cyclaspoides borisovetsi sp. n. was the most abundant species within the bodotriids (33%). Bathycuma sonne sp. n. makes up 15% of the bodotriids. One species of a new genus of the family Pseudocumatidae Sars, 1878 was found (Lavrenteva, 2013). In this work we present the description of three cumacean species new to science, but more than 60 new species remain undescribed, which will be subject of subsequent papers. were produced using a Wacom pen tablet and the software Adobe Photoshop CS3. Only the two basal articles of the exopods were drawn to avoid overloading of the pictures. Selected specimens were dehydrated in an ethyl alcohol and acetone series, transferred to liquid CO2 and dried by the critical point method. These specimens were examined using an Evo 40 (Carl Zeiss) scanning electron microscope. Body length of Cumacea was measured from the tip of the pseudorostrum to the posterior tip of the pleotelson. The article lengths of the appendages were measured as proposed by Mühlenhardt-Siegel (2005). For the description of the setae we follow the terminology proposed by Alberico and Roccatagliata (2008), but we also used the term unequally bifid seta (no armament present) and bifid on distal end on two unequal parts (Fig. 20E) and multifid (the distal end is “split” into many branches). The type specimens (Table 1) are deposited in the Museum of A.V. Zhirmunsky Institute of Marine Biology Far East Branch, Russian Academy of Sciences and in the Zoological Museum of Hamburg. 2. Materials and methods 2.1. Abbreviations The material for this study was collected during the KuramBio (Kurile Kamchatka Biodiversity Studies) deep-sea expedition on board of the RV “Sonne” in July–September 2012 (for details see Brandt and Malyutina, 2015). Specimens were sampled using a cameraepibenthic sledge (C-EBS). It was successfully deployed 21 times at 12 stations in the Kurile Kamchatka area (two deployments at each station except stations 223-3, 223-4, 223-12 with one deployment of the C-EBS). The sampled material was washed on board immediately with cold sea water through sieves with a mesh size of 300 μm and then preserved with cooled 96% ethanol (first deployment) or 4% formalin (second deployment). After 48 h the material from second deployment was washed and fixed in 70% ethanol. The morphological study and drawing of the figures were performed using a stereomicroscope (Carl Zeiss, V.8) equipped with a camera lucida. The appendages were dissected, mounted in glycerin on slides and examined under the Olympus CX31 microscope equipped with a camera lucida. The pencil drawings were scanned and saved in digital format and the final line drawings The following abbreviations are used in the text and figures: MIMB—Museum of A.V. Zhirmunsky Institute of Marine Biology, Vladivostok; ZMH—Zoological Museum, Hamburg; A1—antenna 1; A2—antenna 2; Md—mandibles; lMd—left mandible; Mx1—maxilla 1; Mx2—maxilla 2; Mxp1–3—maxillipeds 1–3; P1–5—pereopods 1–5; Pl—pleopod I, juv—juvenile, ♀—female, and ♂—male. 3. Taxonomy 3.1. Family Leuconidae Sars, 1878 3.1.1. Abyssoleucon gen. n. 3.1.1.1. Diagnosis. Long serrated dorsomedian line on the carapace; teeth ventrally of the pseudorostrum; subrostral tooth relatively small, ending at level of ocular lobe; first antenna with accessory flagellum as long as the basal article of the main flagellum; female Table 1 Stations at which new species were found. Station Fixative Date Depth (m) Trawling (from–to) Specimens Abyssoleucon tzarevae gen. n., sp. n. 223-3-9 Ethanol 96% 223-4-3 Ethanol 96% 05.08.2012 06.-07.08.2012 4859–4863 5681–5780 47.23071N 154.69821E 47.24771N 154.71971E 46.96401N 154.53981E 46.97471N 154.55651E 54♀, 26♂ 28♀, 11♂ Cyclaspoides borisovetsi sp. n. 223-2-9 Ethanol 96% 223-5-9 Ethanol 96% 223-7-9 Ethanol 96% 223-8-9 Ethanol 96% 223-9-9 Ethanol 96% 223-12-4 Ethanol 96% 223-9-12 Formalin 4% 223-2-10 Formalin 4% 223-5-10 Formalin 4% 223-8-12 Formalin 4% 223-10-12 Formalin 4% 223-11-12 Formalin 4% 03.08.2012 11.08.2012 17.08.2012 20.08.2012 23.08.2012 31.08.2012 24.08.2012 03.08.12 11.08.12 21.08.12 27.08.12 31.08.12 4830–4864 5376–5379 5216–5223 5125–5140 5399–5408 5215–5228 5392–5397 4859–4863 5375–5379 5115–5124 5249–5262 5348–5351 46.22681N 155.55671E 46.24871N 155.54281E 43.59131N 153.96471E 43.57171N 153.96931E 43.04731N 152.99051E 43.02481N 152.97271E 42.24471N 151.73511E 42.23781N 151.70821E 40.59131N 150.99871E 40.57081N 150.99851E 39.73001N 147.18131E 39.70821N 147.15621E 40.59181N 150.99761E 40.57131N 150.98641E 46.22601N 155.55951E 46.24991N 155.54381E 43.59121N 153.96351E 43.56991N 153.96911E 42.24531N 151.73911E 42.23871N 151.71571E 41.19391N 150.09281E 41.21691N 150.09421E 40.21841N 148.10881E 40.20181N 148.09231E 10♀, 1♂, 1 juv 2♀ 1♀ 3♀, 1♂ 3♀, 1♂ 4♀ 1♀, 2 juv 5♀, 2♂, 3 juv 1♀, 1♂ 1♀, 1 juv 2 juv 1♀ Bathycuma sonne sp. n. 223-2-9 Ethanol 96% 223-1-11 Formalin 4% 223-2-10 Formalin 4% 223-5-10 Formalin 4% 223-6-12 Formalin 4% 223-8-12 Formalin 4% 03.08.12 30.07.12 03.08.12 11.08.12 15.08.12 21.08.12 4830–4864 5412–5418 4859–4863 5375–5379 5291–5307 5115–5124 46.22681N 155.55671E 46.24871N 155.54281E 43.97251N 157.32901E 43.97681N 157.30221 46.22601N 155.55951E 46.24991N 155.54381E 43.59121N 153.96351E 43.56991N 153.96911E 42.49151N 153.99891E 42.47041N 153.99531E 42.24531N 151.73911E 42.23871N 151.71571E 2♀, 3♂, 4 juv 1 1♀, 2♂, 2 juv 1♀ 2 juv 1 juv A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 with exopods on pereopods 1–3, male with exopods on pereopods 1–4; teeth on the basal article of the exopods of maxilliped 3 and pereopod 1, tooth on exopods basal article of pereopod 2 and pereopod 3; uropod endopod two-segmented; no pleopods in male. 3.1.1.2. Remarks to genus. The new genus shares some characters with the genus Bytholeucon Watling, 1991, e.g., teeth ventrally of the pseudorostrum, teeth on the basal article of the exopods of maxilliped 3 and pereopod 1; the accessory flagellum of the antenna 1 is approximately as long as the basal article of the main flagellum. However, there are some discriminating characters: there are no pleopods in males of the new genus, vs. one pleopod in Bytholeucon; the antennal notch is narrow in the new genus, but is wider in Bytholeucon; the antennal notch reaches backwards behind 303 the anterior tip of the ocular lobe in the new genus, vs. it reaches maximal to the level of the ocular lobe in Bytholeucon; the subrostral tooth is relatively small in the new genus not extending beyond the level of the ocular lobe, but is strong and almost reaching the tip of the pseudorostrum in Bytholeucon; in the new genus there are more dorsomedian teeth (21) on the carapace than in the known Bytholeucon species (max. 14). Some genera occur in the family Leuconidae without pleopods in male, but like the new genus only Hemileucon Calman, 1907 has a long serrated dorsomedian line on the carapace. The uropod endopod is two-segmented and the accessory flagellum is almost as long as the basal article of the main flagellum in the first antenna, which is comparable to the new genus. There are only three known species in this genus, H. comes Calman, 1907 and H. uniplicatus Calman, 1907 described for the shallow waters of New Zealand, H. bidentatus Liu & Fig. 1. Abyssoleucon tzarevae sp. nov. holotype (MIMB 29046): (A) habitus seen from above. (B) Habitus in lateral view. Scale bar: 1 mm. Paratype female (MIMB 29048): (C) pleotelson and uropods. Scale bar 0.3 mm. (D) Anterior part of carapace in ventral view. Paratype female (MIMB 29050): (E) pleotelson and uropods in ventral view. 304 A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Fig. 2. Abyssoleucon tzarevae sp. nov. paratype female (MIMB 29048): antenna 1. Scale bar: 0.3 mm. Antenna 2, left and right mandibles, maxilla 1, maxilla 2, maxillipeds 1–2. Scale bar: 0.1 mm. Liu, 1990 was found in the littoral zone of the Yellow Sea. The latter might not even be allocated to the correct generic position (Roccatagliata, pers. comm.). Two species from New Zealand possess lateral ridges on the carapace, and the species from the Yellow Sea has two (female) or no (male) dorsomedian teeth on the carapace. All three species have a short subrostral tooth ending at the level of anterior tip of the ocular lobe. All things considered, we decided to assign the specimen of the Kuril–Kamchatka Trench to a new genus. 3.1.1.3. Etymology. The new genus is named Abysso – because it is distributed in abyssal depth, and – leucon, the stern genus of the family Leuconidae. 3.1.2. Abyssoleucon tzarevae sp. Nov. (Figs. 1–6 and 20). 3.1.2.1. Material examined. Holotype: (MIMB 29046), ovigerous female (3.5 mm), KuramBio, RV “Sonne”, C-EBS, station 223-3-9, 05.08.2012, 4859–4863 m, approximately 47.241N and 154.701E. Paratypes: adult male (allotype, 2.9 mm) (MIMB 29047), collected with holotype; ovigerous female (3.4 mm) (MIMB 29048) and adult male (without pleon) (MIMB 29049) used for dissection, collected with holotype; 4 females and 1 male from station 223-3-9 (MIMB 29050); 4 females and 2 males from station 2233-9 (ZMHK-44210); 2 females and 2 males for SEM (MIMB 29051), collected with holotype. A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 305 Fig. 3. Abyssoleucon tzarevae sp. nov. paratype female (MIMB 29048): maxilliped 3, pereopods 1–5. Scale bar: 0.3 mm. Additional material: 42 females and 19 males collected with holotype (MIMB 29052); 28 females and 11 males KuramBio C-EBS station 223-4-3 (MIMB 29053). long setulate setae ventrally (for additional information see paratypes Fig. 1D; SEM Fig. 20A–C, F, and G). Description of appendages based on paratype, ovigerous female: 3.1.2.2. Etymology. The name of the new species honors the carcinologist Ludmila Alekseevna Tzareva, who has studied the cumaceans of the seas of Russia. Antenna 1 (Fig. 2A1) article 1 with 1 simple seta distally; article 2 with 1 simple seta and 1 setulate seta on distal margin; article 3 slightly longer than article 2, with 2 small simple setae and 1 setulate seta distally; accessory flagellum 0.7 article 3, as long as basal article of main flagellum, with 3 apical simple setae; main flagellum tri-articulated, basal article longest, with 2 simple setae; second article with 1 simple seta distally and 1 simple seta proximally; terminal article with 1 aesthetasc and 3 simple setae. Antenna 2 (Fig. 2A2) tri-articulated, with 3 apical setae. 3.1.2.3. Description. Holotype, female: carapace (Fig. 1A and B) longer than free thoracic segments, with 21 dorsomedian teeth up to posterior end; pseudorostrum 0.2 length of carapace with 3 teeth ventrally; branchial siphon shorter than pseudorostrum; ocular lobe reduced; eyes missing; antennal notch relatively narrow, reaches backwards behind the anterior tip of the ocular lobe; anteroventral margin serrate with 7 teeth, first tooth largest. Five free thoracic segments visible, second segment widest, followed by the third. Pleon with uropods 1.3 as long as carapace and free thoracic segments combined; pleonites 1–4 with pair of Right mandible (Fig. 2, Md) incisor with 4 teeth and 1 serrate seta; pars incisiva with 2 simple setae. Left mandible (Fig. 2, Md) as right, but with well-developed lacina mobilis. 306 A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Fig. 4. Abyssoleucon tzarevae sp. nov. allotype adult male (MIMB 29047): (A) habitus seen from above. (B) Habitus in lateral view. Scale bar: 1 mm. Paratype male (MIMB 29050): (C) pleotelson and uropods. Scale bar 0.3 mm. Maxilla 1 (Fig. 2, Mx1) outer endite with 12 cuspidate setae distally and 1 long simple seta on outer distal corner; inner endite with 2 setulate and 2 simple setae, palp missing. Maxilla 2 (Fig. 2, Mx2) both lobes with 3 long simple setae and 1 setulate seta distally; endite of protopod shortest, with 7 long simple setae, 2 long setulate setae, 3 setulate setae of medium length, 4 small setulate setae and 7 small simple setae. Maxilliped 1 (Fig. 2, Mxp1) basis endite with 4 simple setae, 2 robust setulate setae and 1 setulate seta distally, inner margin with 1 simple seta and 1 setulate seta; merus as long as dactylus, with 1 setulate seta distally and 2 tees on outer margin; carpus 1.5 times longer than merus, with 5 setulate setae on inner margin, 16 simple setae and 1 long setulate seta distally; propodus slightly longer than merus, with 1 long setulate seta distally; dactylus with 1 robust setulate seta and 1 strong simple seta distally. Maxilliped 2 (Fig. 2, Mxp2) basis length–width ratio 2.5; merus to dactylus length–width ratios: 2.1; 1.7; 1.5; 2; basis 0.4 length of appendage, with 1 long setulate seta distally; merus 1.3 times longer than carpus, with 1 long robust setulate seta distally, and 6 small simple setae laterally; carpus with 2 simple and 2 setulate setae on inner distal margin; propodus 0.6 carpus length, with 4 simple setae distally and 1 strong setulate seta on proximal outer margin; dactylus 0.6 propodus length, with 1 cuspidate apical seta and 2 simple setae. Maxilliped 3 (Fig. 3, Mxp3) ischium to dactylus length–width ratios: 3.8; 0.8; 1.6; 2.7; 1.8; 2.3; basis 1.6 times longer than rest of appendage, with 4 setulate setae (two of them very long) on A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 307 Fig. 5. Abyssoleucon tzarevae sp. nov. paratype adult male (MIMB 29049): antenna 1, antenna 2, left mandible, maxilla 1. Scale bar: 0.1 mm. Maxilliped 3. Scale bar: 0.3 mm. outer distal corner and 8 setulate setae on inner margin; ischium almost twice shorter than merus; merus 3/4 carpus length, with 1 very long setulate seta, 2 short setulate setae distally and 1 small tooth distally; carpus with 4 short setulate setae on inner margin, 1 long setulate seta and 1 small tooth on outer distal corner; propodus 0.6 carpus length, with 4 short setulate setae distally; dactylus slightly shorter than propodus, with 4 apical simple setae; exopod with 5 teeth at outer margin of basal article. Pereopod 1 (Fig. 3, P1) basis to dactylus length–width ratios: 5.5; 1; 3.5; 7.8; 7.4; 6.1; basis 0.4 length of appendage, with 5 long setulate setae on inner margin, 1 setulate seta on outer distal corner and 4 teeth (2 strong and 2 small) on distal third; ischium 0.3 merus length, with 1 simple seta laterally; merus and dactylus equal in length, merus with 1 simple seta and 1 setulate seta distally; carpus second longest article, 1.8 times longer than merus and 1.2 times longer than propodus, with 5 simple setae on distal margin and 1 setulate seta laterally; propodus with 3 simple setae distally, and 1 simple seta on each, inner and outer margins; dactylus with 6 terminal simple setae and 1 seta laterally; exopod basal article with 6 teeth on outer margin. Pereopod 2 (Fig. 3, P2) basis to dactylus length–width ratios: 4.8; 0.6; 1.9; 3.7; 2.5; 6.9; basis slightly shorter, than rest of 308 A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 appendage, with 4 long setulate setae and 1 simple seta on inner margin; ischium with 1 long setulate seta on inner distal corner; merus three times longer than ischium, with 1 long setulate seta on inner distal corner, with 1 simple seta and 1 setulate seta on outer distal corner; carpus 1.5 times longer than merus, with 3 long setulate setae distally and 1 simple seta; propodus 0.6 carpus length, and twice shorter than dactylus; dactylus with 5 apical simple setae, 1 simple seta on outer margin and 1 setulate seta on inner margin; exopod basal article with tooth. Pereopod 3 (Fig. 3, P3) basis to dactylus length–width ratios: 7.1; 1; 1.2; 3.1; 2.3; 1.7; basis one and half from rest of appendage, with 7 long setulate setae; ischium slightly shorter than merus, with 1 simple seta and 1 setulate seta; carpus twice longer than propodus, with 2 long simple setae distally; propodus slightly longer than merus, with 1 long simple seta distally; dactylus twice shorter than merus, with 2: long and short terminal simple setae; exopod basal article with tooth. Pereopod 4 (Fig. 3, P4) basis to dactylus length–width ratios: 6.3; 1; 1.6; 3.9; 3; 2.2; basis longest article, little longer than rest of appendage, with 2 setulate setae and 5 unequal simple setae; ischium with 2 long setulate setae distally and 1 small simple seta laterally; merus 1.4 times longer than ischium with 1 setulate seta distally; carpus 1.4 times longer than merus with 1 long setulate seta and 1 small simple seta laterally, and 3 unequal simple setae distally; propodus little longer than merus, with 1 simple seta distally; dactylus twice shorter than propodus with 1 long apical simple seta. Fig. 6. Abyssoleucon tzarevae sp. nov. paratype adult male (MIMB 29049): pereopods 1–5. Scale bar: 0.3 mm. A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Pereopod 5 (Fig. 3, P5) basis to dactylus length–width ratios: 6.1; 1.2; 1.2; 3.2; 2.7; 2.6; basis 0.8 length of the rest of appendage, with 1 setulate seta distally; ischium and merus are subequal in length, both with 1 setulate seta distally; carpus 2.2 times longer than merus, with 1 setulate seta mid-way along article and 2 simple setae distally, propodus 0.6 carpus length, with 1 long simple seta distally; dactylus almost twice shorter than propodus with 2: 1 long and 1 short apical simple setae. Pleotelson (Fig. 1A–C, and E) slightly longer than wide, two times shorter than pleonite 5, anal valves visible in dorsal view. Uropod (Figs. 1C, 20D and E) peduncle 1.3 times longer than pleotelson, with 3 unequally bifid setae on inner margin and 3 unequally bifid setae on dorsal surface; exopod two-articulated, proximal article 0.4 length of distal one, distal article: inner margin with 7 setulate setae, outer margin with 4 simple setae, distal end with 2 unequal setae; endopod two-articulated, slightly shorter than exopod, basal article almost twice as long as distal article, basal article with 5 unequally bifid setae and distal article with 3 unequally bifid setae on inner margin and 1 long terminal seta. Male similar to female, but carapace (Fig. 4A and B) with 10 dorsomedian teeth on anterior part of carapace and 5 on posterior 309 part; pseudorostrum relatively slightly shorter than that of female with 2 teeth ventrally; antennal notch not pronounced, anteroventral margin with 3 teeth, pleonites 1–2 with pair of long setulate setae ventrally (for additional information see male paratype SEM Fig. 20H and I). Antenna 1 (Fig. 5A1) article 1 longest, with 5 simple setae and 1 setulate seta; article 2 with 1 simple seta and 2 setulate setae on distal margin; article 3 slightly shorter than article 2, with 1 small simple seta and 1 setulate seta; accessory flagellum longer than 2 basal articles of main flagellum, with 3 apical and 2 lateral simple setae; main flagellum five-articulated, basal article with 4 long simple setae; articles 3 and 4 with 1 simple seta distally; terminal article with 2 aesthetascs and 1 simple seta. Antenna 2 (Fig. 5A2) reaches pereonite 5; article 2 with 2 small setulate setae laterally; article 3 slightly shorter than article 2, with 1 setulate seta laterally; article 4 slightly longer than articles 2 and 3 combined; article 5 1.75 times longer than article 4; two distal articles covered with rows of numerous transverse simple setae of different length; flagellum has at least 16 articles. Left mandible (Fig. 5, lMd) similar to that of female, 4 teeth on lacinia mobilis visible. Fig. 7. Cyclaspoides borisovetsi sp. nov., holotype (MIMB 29054): (A) habitus seen from above. (B) Habitus in lateral view. Scale bar: 1 mm. Paratypes females: (C) pleotelson and uropods (MIMB 29055). (D) Pleotelson and uropods peduncles in ventral view (MIMB 29057). Scale bars 0.5 mm. 310 A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Fig. 8. Cyclaspoides borisovetsi sp. nov., paratype female (MIMB 29055): antenna 1, labium, left mandible, maxilla 1, maxillipeds 1–2. Scale bars: 0.3 mm. Maxilla 1 (Fig. 5, Mx1) similar to that of female, with long palp. Maxilliped 3 (Fig. 5, Mxp3) as female, except for: basis covered by numerous small simple setae on inner and outer margins; basal article of exopod with row of setulate setae and 8 small teeth on outer margin; other differences in number of setae are insignificant. Pereopod 1 (Fig. 6, P1) similar to that of female, but more armed: some setae much longer than that of female; basis with 1 long setulate seta on inner distal margin in addition to female; merus with additional 1 setulate seta distally and 1 setulate seta instead of simple; carpus with 7 setulate setae and 2 simple setae (in female 1 setulate seta and 5 simple setae). Pereopods 2–4, bases wider (especially proximal part) than in female. Pereopod 2 (Fig. 6, P2) basis to dactylus length–width ratios: 3.5; 0.3; 1.6; 3.9; 2.8; 8.9; (female basis, ischium and merus more slender); basis slightly longer than rest of appendage; other details similar to those of male, insignificantly differing in proportions and number of setae. Pereopods 3 and 4 have some differences from that of female. Pereopod 3 (Fig. 6, P3) basis to dactylus length–width ratios: 3.8; 0.9; 1.6; 3.9; 2.6; 2.1; length proportions of articles similar to those of female, but merus relatively slightly longer than that of female. There are different setal armaments than that of female: basis with 2 setulate setae laterally and 1 setulate seta distally; ischium with 2 long simple setae distally instead of 1 setulate seta and 1 simple seta in female; merus with 1 setulate seta laterally; carpus with additional 1 setulate seta on each lateral margin. Pereopod 4 (Fig. 6, P4) basis length–width ratio 3.8 in proximal part; insignificantly differing in other proportions, and number of setae. A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 311 Fig. 9. Cyclaspoides borisovetsi sp. nov., paratype female (MIMB 29055): maxilliped 3, pereopods 1–5. Scale bar: 0.3 mm. Pereopod 5 (Fig. 6, P5) similar to that of female, it insignificantly differs in proportions and setal armament. The first four pairs of pereopods and maxilliped 3 with well developed exopods. Uropod (Fig. 4C) peduncle 1.5 times longer than pleotelson, with 3 setulate setae on inner margin and 3 simple setae on dorsal surface; exopod two-articulated, proximal article 0.3 length of distal one, distal article: inner margin with 7 setulate setae, outer margin with 3 simple setae, distal end with 2 unequal setae; endopod two-articulated, as long as exopod, basal article twice as long as distal article, basal article with 7 unequally bifid setae and distal article with 5 unequally bifid setae on inner margin and 1 long terminal seta. 3.1.2.4. Distribution. NW Pacific, western slope of the Kuril– Kamchatka Trench, 4859–5780 m. 3.1.2.5. Remarks. see Remarks for the genus. 3.2. Family Bodotriidae T. Scott, 1901 3.2.1. Cyclaspoides borisovetsi sp. Nov. (Figs. 7–12 and 21A–F). 312 A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Fig. 10. Cyclaspoides borisovetsi sp. nov., allotype male (MIMB 29061): (A) habitus seen from above. (B) habitus in lateral view. Scale bar: 1 mm. (C) Pleotelson and uropods. Scale bar: 0.5 mm. paratype females (MIMB 29057) (D) and (E): the closing mechanism of the siphonal tubes seen from ventral. Scale bar: 0.3 mm. 3.2.1.1. Material examined. Holotype: (MIMB 29054), ovigerous female (5 mm), KuramBio, RV “Sonne”, C-EBS, station 223-2-9, 03.08.2012, 4830–4864 m, approximately 46.241N and 155.551E. Paratypes: adult male (allotype, 5.5 mm) (MIMB 29061), KuramBio, RV “Sonne”, C-EBS, station 223-8-9, 20.08.2012, 5125– 5140 m, approximately 42.241N and 151.721E. Ovigerous female (4.8 mm) (MIMB 29055) and subadult male (without pleotelson) (MIMB 29056) used for dissection, collected with holotype; 3 females from station 223-9-9 (ZMHK-44211); immature male from station 223-9-9 (ZMHK-44212); 3 females from station 2232-9 (MIMB 29057); 3 females (for SEM) from station 223-12-4 (MIMB 29063). Additional material: 4 females and 1 juvenile from station 2232-9 (MIMB 29058); 2 females from station 223-5-9 (MIMB 29059); 1 female from station 223-7-9 (MIMB 29060); 3 females from station 223-8-9 (MIMB 29062); 1 female from station 223-12-4 (MIMB 29064); 1 female and 2 juveniles from station 223-9-12 (MIMB 29065); 5 females, 2 males and 3 juveniles from station 223-2-10 (MIMB 29066); 1 female and 1 male from station 223-510 (MIMB 29067); 1 female and 1 juvenile from station 223-8-12 (MIMB 29068); 2 juveniles from station 223-10-12 (MIMB 29069); 1 female from station 223-11-12 (MIMB 29070). 3.2.1.2. Etymology. The species is named in honor of Evgenii Emmanuilovich Borisovets, the head of the laboratory of commercial invertebrates of Far Eastern Seas at Pacific Fisheries Research Center (TINRO-Center) and one of the best lecturers of Far Eastern Federal University. A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 313 Fig. 11. Cyclaspoides borisovetsi sp. nov., paratype male (MIMB 29056): antenna 1, left mandible, maxilla 2, maxillipeds 2–3. Scale bars: 0.3 mm. 3.2.1.3. Diagnosis. Carapace evenly convex from dorsal side; very weak dorsal ridge running on each side from the posterior end of the frontal lobe fissure a short distance dorso-anteriorly, bending backwards and meeting before the posterior third in the dorsomediane line; ocular lobe very small; branchial siphon 0.5 as long as pseudorostrum or concealed; anteroventral margin of carapace serrate with 6–8 teeth; uniarticulated uropod endopod on inner margin with 5 cuspidate setae in female (13 in male); uropod peduncle shorter than pleotelson. 3.2.1.4. Description. Holotype, female: carapace (Fig. 7A and B) 0.4 of total body length, oviform seen from above; a very weak dorsal ridge running on each side from the posterior end of the frontal lobe fissure a short distance dorso-anteriorly, bending backwards and meet before the posterior third in the dorsomediane line; ocular lobe very small, eyes missing; pseudorostrum moderately long, branchial siphon 0.5 as long as pseudorostrum or concealed; antennal notch deep, anteroventral margin serrate with 6 teeth. Pereonite 1 not visible, pereonite 2 completely fused with carapace (very weak line on a coalescing place) and pereonite 3 fused dorsally with carapace. Pleon length 0.5 total body length, with lateral articular processes. Pleotelson little longer than pleonite 5 and as long as uropods (for additional information see female paratypes SEM Fig. 21A–F). Description of appendages based on paratype, female with marsupial plates. Antenna 1 (Fig. 8A1) articles 1–3 length–width ratios: 2.6; 4.3; 6.1; basal article slightly longer than article 2 and 0.9 length of distal article, flagella missing. Left mandible (Fig. 8, lMd) incisor with 5 teeth; lacinia mobilis with 3 teeth; pars incisiva with 16 setulate setae. Labium as shown in Fig. 8. Maxilla 1 (Fig. 8, Mx1) outer endite with 11 cuspidate serrulate setae distally and numerous small setae along outer margin and on inner distal corner; inner endite with 5 setae (2 small setulate, 1 robust, 1 trifid and 1 multifid). Maxilliped 1 (Fig. 8, Mxp1) basis endite with 8 setae on inner margin (2 simple, 2 robust setuloserrulate, 1 robust setulate, 1 unequally bifid seta, and 2 cuspidate setae), many very small simple setae and 6 apical setae (3 small simple, 1 setulate and 2 unequally bifid setae); carpus inner distal margin with 3 simple setae, 2 long unequally bifid setae and 4 serrate setae; propodus with 1 small and 1 long setulate setae and with 3 serrate setae on inner distal margin; dactylus with 3 simple setae. 314 A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Fig. 12. Cyclaspoides borisovetsi sp. nov., paratype male (MIMB 29056): pereopods 1–5, pleopod juvenile male. Allotype male (MIMB 29061): pleopod adult male. Scale bar: 0.3 mm. Maxilliped 2 (Fig. 8, Mxp2) basis to dactylus length–width ratios: 3.1; 0.3; 0.9; 1.8; 1.5; 2.2; basis 1.3 times longer than rest of appendage with 1 setulate seta on inner distal corner; ischium convex on inner margin, 0.3 merus length; merus and carpus convex on outer margin, with 1 and 2 setulate setae on inner distal margin respectively, merus length 0.8 length of carpus; propodus 0.7 carpus length with 2 setulate setae on distal margin and 3 simple setae on inner distal corner; dactylus slightly shorter than propodus, with 6 simple setae on distal margin; basis, merus, carpus and propodus covered with rows of many very small simple setae. Maxilliped 3 (Fig. 9, Mxp3) ischium to dactylus length–width ratios: 1.1; 0.8; 2.4; 3.2; 4.2; basis 1.8 times longer than rest of appendage, more slender in the middle, expanded distally reaching 1/3 merus length, with 2 long setulate setae on projection end, with 3 setulate setae on inner margin of distal prolongation; ischium as long as merus (without prolongation); merus distal prolongation reaching beyond carpus/ propodus articulation with 1 long setulate seta on its end; carpus 1.5 times longer than merus, with 2 setulate setae on distal margin (on inner and outer corners) and with 4 small simple setae on inner margin; propodus 0.9 carpus length, with 1 setulate seta on outer corner and 1 simple seta on inner corner, inner and outer margins with several small simple setae; dactylus 0.7 propodus length, with 4 long apical simple setae and with several small simple setae mostly on inner margin; exopod present. Pereopod 1 (Fig. 9, P1) basis to dactylus length–width ratios: 2.7; 1.3; 2.4; 5.1; 6.1; 4.3; basis little longer than rest of appendage; ischium 34 merus length and twice shorter than carpus; carpus and propodus equal in length; dactylus almost half length of propodus, with 1 simple seta proximally and 3 apical setae; exopod present. 315 A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Pereopod 2 (Fig. 9, P2) ischium fused with basis; length–width ratios: basis–ischium 6.6, merus to dactylus 1.4; 2; 1.7; 3.7; basis–ischium little longer than rest of appendage, with 1 simple seta distolaterally; merus and propodus subequal in length; merus with 1 seta distally; merus 1.3 times longer than carpus; dactylus second longest article, 1.9 times longer than propodus, with 3 apical long simple setae. Pereopod 3 (Fig. 9, P3) basis to dactylus length–width ratios: 5.6; 1; 2.2; 3; 2; 5.5; basis equal in length to the rest of appendage; ischium and propodus subequal in length; ischium with 2 simple setae on distal corner; merus and carpus same length; carpus twice longer than propodus; basis, merus and carpus with long seta on distal corner; dactylus little shorter than propodus with 1 long and 1 short apical simple setae. Pereopod 4 (Fig. 9, P4) basis to dactylus length–width ratios: 7.5; 1.4; 1.9; 3.8; 2.6; 4.4; basis longest article, little shorter than rest of appendage, ischium and propodus equal in length; merus 0.8 carpus length, 1.5 times longer than ischium, with 1 long simple seta on outer distal corner; carpus three times longer than dactylus. Pereopod 5 (Fig. 9, P5) basis to dactylus length–width ratios: 5.1; 1; 1.7; 3.5; 2.7; 3.4; basis 0.6 length of the rest of appendage; length ratio ischium to dactylus similar to pereopod 4; basis, ischium and merus with 1 long simple seta distally; carpus with 2 long simple setae distally; dactylus with 1 long and 1 short apical simple setae. Uropods (Fig. 7C and D) as long as pleotelson, peduncle with 2 short simple setae on inner margin; endopod 1-articulated, almost equal in length to peduncle and 0.9 length of exopod, with 5 cuspidate setae on inner margin and a long terminal setulate seta; exopod 2-articulated, with 1 short simple seta on inner margin and 2 cuspidate setae on outer margin; distal article 0.8 total exopod length. Male similar to female, 5.5 mm long. Carapace (Fig. 10A and B) narrower, anteroventral margin with 8 teeth. Uropods 1.2 times longer than pleotelson. Pleonites higher than in female, with 1–5 pleopods. Antenna 1 (Fig. 11A1) articles 1–3 length–width ratios: 2.3; 4.2; 5.6; basal article arched, flagella missing. Left mandible (Fig. 11, lMd) similar to that of female. Maxilla 2 (Fig. 11, Mx2) lateral lobe of endite with 7 long setae distally which are shortening from outer to inner margin; inner lobe of endite with 6 long setae distally; endite of protopod shortest, with two rows of setae distally: one row with 2 long setulate setae and 14 simple setae of various length, second row with 2 robust setae and 3 robust setulate setae (2 of them with long setules); inner margin with numerous simple setae of various length. Maxilliped 2 (Fig. 11, Mxp2) similar to that of female. Maxilliped 3 (Fig. 11, Mxp3) similar to that of female, but basis, ischium and merus with setulate seta on inner corner; basis with 1 additional setulate seta on inner margin of projection end; carpus with 2 setulate setae on inner margin. Pereopod 1 (Fig. 12, P1) similar to that of female, but carpus slightly longer than propodus; basis with 1 setulate seta distally. Pereopod 2 (Fig. 12, P2) similar to that of female, but basis– ischium equal in length to the rest of appendage; dactylus 1.4 times longer than propodus. Pereopod 3 (Fig. 12, P3) similar to that of female, but carpus relatively longer than at female, with 3 long simple setae. Pereopod 4 (Fig. 12, P4) more armed than that of female (1 long simple seta distally on basis, ischium, merus and propodus; 2 long simple setae on carpus distal margin, but similar in proportions). Pereopod 5 (Fig. 12, P5) similar to that of female. Pereopod 1 and maxilliped 3 with well developed exopods. Pleopods (Fig. 12, Pl juv and adult) as illustrated. Uropods (Fig. 10C) more armed than that of female, 1.2 times longer than pleotelson, peduncle with 6 long setulate setae on inner margin; endopod with 13 cuspidate setae of various length on inner margin; exopod with 1 simple and 1 setulate seta on inner magin and 3 cuspidate setae on outer magin. 3.2.1.5. Distribution. North-western Pacific, Kuril–Kamchatka abyssal plains, 4830–5408 m. 3.2.1.6. Remarks. There are six species known from the genus Cyclaspoides (Table 2; Fig. 13). Only two species are described until now for the Pacific: Cyclaspoides erugatus Corbera, 2008 from south-western Pacific and C. bacescui Petrescu, 1995 from the south-eastern Pacific. The vertical distribution of the genus Cyclaspoides covers the depth range from 0.5 to 5387 m (Table 2). Most of the species are bathyal and abyssal species: C. bacescui and C. erugatus inhabiting the lower bathyal zone, C. pellucidus Day, 1978 in the upper bathyal zone, C. longimerus Mühlenhardt-Siegel, 2005 and C. borisovetsi sp. n. of abyssal origin. C. sarsi Bonnier, 1896 shows the widest vertical range and Fig. 13. The geographical distribution of the genus Cyclaspoides. Table 2 The distribution of the species belonging to genus Cyclaspoides. Species Cyclaspoides Cyclaspoides Cyclaspoides Cyclaspoides Cyclaspoides Cyclaspoides Cyclaspoides bacescui Petrescu, 1995 erugatus Corbera, 2008 flokkeri Mühlenhardt-Siegel, 2000 longimerus Mühlenhardt-Siegel, 2005 pellucidus Day, 1978 sarsi (Bonnier, 1896) borisovetsi sp. n. Depth (m) Location Region 1892–3279 2100–2470 0.5–1 5387 400–800 698–4934 4830–5380 Ecuador, Chile New Caledonia Seychelles Angola Basin South Africa Northern and tropical Atlantic Kuril–Kamchatka Trench SE Pacific SW Pacific West India SE Atlantic SW Atlantic, West India North Atlantic, Tropical Atlantic NW Pacific 316 A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Fig. 14. Bathycuma sonne sp. nov., holotype (ZMHK-44213): (A) habitus seen from above. (B) Habitus in lateral view. Scale bar: 1 mm. Paratype female (MIMB 29071): (C) Pleotelson and uropods. Scale bar: 0.5 mm. inhabits also the deep sea. The record of the littoral species Cyclaspoides flokkeri Mühlenhardt-Siegel, 2000 is interesting, because this species differs from the other deep-sea species by a number of significant characteristics: the pleotelson is shorter than the uropod peduncle, there are no pigmented eye lenses present, the ocular lobe is well developed; in the other species the pleotelson is longer than the uropod peduncle, and the eyes are reduced. C. borisovetsi sp. n. has significant morphological differences to the other described species. The habitus of the new species is similar to C. erugatus, but differs from it in the uropods armament: uropod endopod of C. borisovetsi sp. n. with five cuspidate setae along the inner margin, exopod with two cuspidate setae on outer margin, versus C. erugatus – with two to three cuspidate setae on endopod, five cuspidate setae on exopod, uropods peduncle has a tooth on inner distal corner (Corbera, 2008). A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 317 Fig. 15. Bathycuma sonne sp. nov., paratype female (MIMB 29071): antenna 1, maxilla 1, maxillipeds 1–3. Scale bars: 0.1 mm. The new species differs from C. bacescui by a short branchial siphon, a straight pseudorostrum and in the uropod endopod armament. C. bacescui has long branchial siphon, pseudorostrum arched downward, uropod endopod with eight cuspidate setae along the inner margin (Petrescu, 1995). C. borisovetsi sp. n. differs from C. flokkeri in shape of a carapace and absence of eyes. C. flokkeri has short pseudorostrum, anteroventral margin not serrate, antennal notch small, well developed eyes present in males (Mühlenhardt-Siegel, 2000). Cyclaspoides borisovetsi sp. n. differs from C. longimerus in the shape of the carapace and the pseudorostrum configuration. For C. longimerus the posterior third of the carapace is convex, the pseudorostrum is long and acuminate (Mühlenhardt-Siegel, 2005). C. borisovetsi sp. n. has an unarticulated uropod endopod, while C. pellucidus has a two-articulated endopod (Day, 1978). The uropod rami of the new species are as long as the pleotelson, that distinguishes it from C. sarsi which uropod rami are shorter than the pleotelson. It is interesting to note that the branchial siphon of some specimens of C. borisovetsi sp. n. is shorter than the pseudorostrum (Fig. 10E), however, in some specimens the siphon is missing and the pseudorostrum looks like closed by a lid (Figs. 10D and 21F). The lid is proximally articulated to the body, when it opens, the branchial siphon can protrude. 3.2.2. Bathycuma sonne sp. Nov. (Figs. 14–19 and 21G and H) 3.2.2.1. Material examined. Holotype: (ZMHK-44213), nonovigerous female (6 mm), KuramBio, RV “Sonne”, C-EBS, station 223-2-9, 03.08.2012, 4830–4864 m, approximately 46.241N and 155.551E. Paratypes: subadult male (allotype, 7.7 mm) (ZMHK-44214 ), non-ovigerous female (5.5 mm) (MIMB 29071) and subadult male (6.5 mm) (MIMB 29072) used for dissection, 1 subadult male and 2 juveniles (MIMB 29073), 2 juveniles (ZMHK-44215) – collected with holotype; 1 male (SEM) from station 223-2-10 (MIMB 29076). Additional material: 2 juveniles from station 223-6-12 (MIMB 29078); 1 ovigerous female (damaged carapace) from station 2235-10 (MIMB 29077); 1 damaged carapace from station 223-1-11 (MIMB 29074); 1 female, 1 male and 2 juveniles from station 223-210 (MIMB 29075); 1 juvenile from station 223-8-12 (MIMB 29079). 318 A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Fig. 16. Bathycuma sonne sp. nov., paratype female (MIMB 29071): pereopods 1–5. Scale bar: 0.3 mm. 3.2.2.2. Etymology. The name of the new species honors the German research vessel “Sonne” on board of which new species were collected. 3.2.2.3. Diagnosis. carapace serrated on anterior half with two rows of 22–28 alternating teeth; antennal notch shallow; anterolateral corner small; pseudorostrum without dorsal teeth, carapace significantly convex in frontal part; maxilliped 3 basis endite as long as ischium; pereopod 2 and basis of pereopod 1 with cuspidate setae. 3.2.2.4. Description. Holotype, female: carapace (Fig. 14A and B) 14 of total body length and little less than twice as long as width, which slightly less than depth; seen from side anterior part of dorsal margin significantly convex; carapace with 26 dorsomedian teeth (two rows of alternating teeth), which run from the tip of ocular lobe and occupies about 1/3 of dorsal margin; antennal notch shallowly concave; anteroventral margin with 16 teeth; ocular lobe very small, eyes missing; pseudorostrum short, truncated at apex seen from above, with 5 small teeth on anterior margin. Length of all thoracic segments about 0.7 of carapace; pleon longer than carapace and free thoracic segments combined; pleonite 5 longest; pleonite 6 with spinules on dorsal margin, slightly shorter than uropods' peduncles, projecting posteriorly on 1/3 of uropods' peduncles length; anal valves visible in dorsal view. Description of appendages based on paratype, female with marsupial plate. Antenna 1 (Fig. 15A1) articles 1–3 length–width ratios: 2.5, 2.3, 2.8; articles 1–1.8 times longer than article 2, with numerous A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 319 Fig. 17. Bathycuma sonne sp. nov., allotype male (ZMHK-44214): (A) habitus seen from above. (B) Habitus in lateral view. Scale bar: 1 mm. Paratype male (MIMB 29072): (C) pleotelson and uropods. Scale bar: 0.5 mm. very small simple setae distally; article 2 slightly shorter than article 3, with 4 small simple setae, flagella missing. Maxilla 1 (Fig. 15, Mx1) outer endite with 12 cuspidate setae distally, 5 small simple setae on inner distal margin and 1 setulate seta on outer distal corner; inner endite with 2 simple setae (1 small, 1 strong), 3 setulate setae and 1 trifid seta distally. Maxilliped 1 (Fig. 15, Mxp1) basis length–width ratio 2.1, longer than remaining articles together, with 4 long simple setae on inner margin and with row of small simple setae, endite with 2 small simple setae distally and 2 setulate setae; merus to dactylus length–width ratios: 1.3, 1, 1.8, 1.8; carpus 2.2 times longer than merus, with 8 setulate setae and 12 simple setae, inner margin with 5 unequally bifid setae; propodus slightly longer than merus, with 3 simple and 1 setulate setae on inner distal corner, and 4 simple setae on outer distal margin; dactylus twice shorter than merus, with 1 long and 1 short apical simple setae. Maxilliped 2 (Fig. 15, Mxp2) basis to dactylus length–width ratios: 4.5; 0.5; 1.5; 2.3; 2.7; 2.9; basis 1.8 times longer than rest of appendage, with 14 small simple setae, distal margin with 3 setulate setae; merus 2.5 times longer than ischium, with 320 A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Fig. 18. Bathycuma sonne sp. nov., paratype male (MIMB 29072): antenna 1, left mandible, maxilla 2, maxillipeds 1–3. Scale bars: 0.3 mm (Mxp 1-3, A1, lMd) and 0.1 mm (Mx2). 1 setulate seta on inner distal corner; carpus 1.3 times longer than merus, with 2 setulate setae on inner distal corner, 5 small simple setae on outer margin and 1 setulate seta distally, propodus slightly shorter than carpus, outer distal corner with 1 setulate seta; 2 setulate and 1 simple setae on inner distal corner; 1 setulate seta in middle of article; dactylus twice shorter than carpus, with 3 small simple setae and 1 cuspidate seta distally. Maxilliped 3 (Fig. 15, Mxp3) basis to dactylus length–width ratios: 6.3; 1.3; 1.5; 2.3; 2.9; 4.1; basis 2.4 times longer than rest of appendage, with row of many small simple setae along inner and outer margins and 3 setulate setae on inner margin, endite as long as ischium, with 4 unequal setulate setae distally (one very long); ischium with 1 setulate seta on inner margin; merus 1.2 times longer than ischium, with 1 setulate seta on outer and 1 setulate seta on inner distal corners; carpus as long as propodus and 1.4 times longer than merus, with 2 setulate setae on inner margin; propodus with 2 small simple setae on outer margin and 1 simple seta on inner distal corner; dactylus as long as merus, with many small simple setae along inner and outer margins and with 5 apical simple setae. Pereopod 1 (Fig. 16, P1) basis to dactylus length–width ratios: 6.8; 1.2; 2.7; 5.3; 8.4; 6.7; basis 0.9 as long as the rest of appendage, with 7 setulate setae laterally (6 of them on proximal half) and 11 cuspidate setae; merus twice longer than ischium and 0.8 dactylus length; propodus 1.4 times longer than carpus, with 3 small simple setae on distal third of the article; dactylus 0.6 propodus length, with 5 apical simple setae. A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 321 Fig. 19. Bathycuma sonne sp. nov., paratype male (MIMB 29072): pereopods 1–5, pleopod juvenile male. Scale bar: 0.3 mm. Pereopod 2 (Fig. 16, P2) basis to dactylus length–width ratios: 3.8; 0.4; 1.8; 2.5; 1.4; 5.5; basis slightly shorter than rest of appendage, with 2 setulate setae on distolateral third of the article and several small simple setae; ischium four times shorter than merus, with 1 setulate seta laterally; merus with 3 cuspidate setae and 1 setulate seta distally; carpus 1.3 times longer than merus, with 2 setulate setae laterally and 4 cuspidate setae (1 on proximal third of the article, and 3 on distal margin); propodus 0.5 merus length; dactylus 3.2 times longer than propodus, with 4 cuspidate setae laterally, 1 long annulate seta and 2 cuspidate setae distally. Pereopod 3 (Fig. 16, P3) basis to dactylus length–width ratios: 4.7; 0.8; 1.3; 3.2; 1.9; 3.3; basis 1.4 times longer than rest of appendage, with several simple setae, with 1 setulate seta distally; ischium, propodus and dactylus same length; ischium with 3 long setae distally (1 simple and 2 annulate four times longer than ischium); merus 1.5 times longer than ischium, with 1 setulate seta; carpus 1.5 times longer than merus, with 2 long simple setae laterally, distal end with 3 (4?) long annulate setae and 1 simple seta; dactylus with 1 terminal cuspidate seta and 1 simple seta. Pereopod 4 (Fig. 16, P4) basis to carpus length–width ratios: 4.8; 1.2; 1.8; 4.3; basis almost as long as ischium, merus and carpus together, with 1 setulate seta distally; ischium 0.8 merus length, with 1 (2?) long annulate seta distally; merus with 1 simple seta and 1 long annulate seta distally; carpus with 1 annulate seta on one lateral margin and 1 long setulate seta on opposite lateral margin. Propodus and dactylus missing. Pereopod 5 (Fig. 16, P5) basis to dactylus length–width ratios: 2.8; 1.1; 1.5; 4.2; 2; 2.2; basis 0.4 as long as the rest of appendage, with 1 simple seta distally; merus 1.5 times longer than ischium, with 1 simple seta distally; carpus slightly longer than basis; propodus as long as ischium; dactylus 0.7 propodus length, with 1 apical cuspidate seta. The first three pairs of pereopods and maxilliped 3 with well developed exopods. Uropod (Fig. 14C) peduncle 1.2 times longer than pleotelson and 1.5 times longer than endopod, with 5 cuspidate setae on inner margin; exopod 1.4 times longer than endopod; exopod twoarticulated, distal article twice longer than proximal, with 2 long apical simple setae; endopod two-articulated, proximal article 1.5 times longer than distal one, with 6 inequal cuspidate setae on inner margin of proximal article, distal article with 4 unequal cuspidate setae on inner distal margin and 1 terminal simple seta. 322 A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Fig. 20. Abyssoleucon tzarevae sp. nov. SEM (MIMB 29051). Paratype female: (A) habitus in lateral view. (B) Anterior part of carapace in lateral view. (F) Sculpture of integument of anterior part of carapace. (G) Sculpture of integument of posterior part of carapace. Paratype female: (C) pseudorostrum in ventral view. Paratype female: (D) pleotelson and uropods. (E) unequally bifid seta (on inner distal corner of uropod peduncle). Paratype adult male: (H) habitus in lateral view, (I) setae on the ventral side of the pleonite 1. A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Male similar to female, but carapace (Fig. 17A, B) with 28 dorsomedian teeth, which reaching on anterior half of the carapace; antennal notch shallower than that of female; anterolateral corner smaller than that of female (for additional information see male paratype SEM Fig. 21G and H). Antenna 1 (Fig. 18A1) similar to that of female, but proximal article covered with numerous very small simple setae, with setulate seta on inner distal margin; flagella missing. 323 Maxilla 2 (Fig. 18, Mx2) inner margin with row of 26 long simple setae; lateral lobe of endite longest, with 3 simple and 5 setulate setae; inner lobe of endite with 6 setulate setae; endite of protopod shortest, with 2 long setulate setae, 15 simple setae of various length and 5 robust setulate setae. Left mandible (Fig. 18, lMd) incisor with 4 teeth; pars incisiva with 15 setulate setae; lacinia mobilis with 4 teeth. Fig. 21. Cyclaspoides borisovetsi sp. nov. SEM (MIMB29063). Paratype female: (A) habitus in lateral view. (B) Sculpture of integument (strait lateral view). (E) Anterior part of carapace in lateral view. Paratype female: (D) anterior part of carapace in dorsal view. (C) Sculpture of integument (oblique lateral view). Paratype female: (F) pseudorostrum in ventral view. Bathycuma sonne sp. nov. SEM (MIMB 29076). Paratype subadult male: (G) carapace in lateral view. (H) Sculpture of integument. 324 A.V. Lavrenteva, U. Mühlenhardt-Siegel / Deep-Sea Research II 111 (2015) 301–324 Maxilliped 1 (Fig. 18, Mxp1) similar to that of female except additional 1 long simple seta on basis inner margin and 1 unequally bifid seta on carpus inner margin. Maxilliped 2 (Fig. 18, Mxp2) and maxilliped 3 (Fig. 18, Mxp3) similar to that of female, insignificantly differing in proportions and setal armament. Pereopod 1 (Fig. 19, P1) similar to that of female, but propodus and dactylus more slender and relatively longer than that of female and covered with small simple setae. Pereopod 2 (Fig. 19, P2) similar to that of female, but carpus with 4 additional cuspidate setae distally. Other differences are insignificant. Pereopod 3 (Fig. 19, P3) similar to that of female. Pereopod 4 (Fig. 19, P4) propodus as long as ischium; dactylus 3/4 length of propodus, with 1 apical cuspidate seta and 2 small simple setae. Basis–carpus similar to that of female except for: basis with several small simple setae laterally; carpus with 2 long setulate setae on lateral margin and 4 long annulate setae on distal end (broken in female?). Pereopod 5 (Fig. 19, P5) basis and ischium with 1 simple seta on distal margin, basis 4.2 times longer than ischium. Merus, carpus, propodus and dactylus missing. First four pairs of pereopods and maxilliped 3 with well developed exopods. Five pairs of pleopod buds on abdomen (Figs 20 and 21). Uropod (Fig. 17C) proportions similar to that of female; peduncle slightly longer than pleotelson with 5 long and 1 short cuspidate setae on inner margin and with serration along outer margin; exopod with 3 simple setae on outer distal margin and 2 (or more?) apical simple setae; endopod proximal article serrated on outer margin, with 8 cuspidate setae on inner margin (from proximal to distal: 3 short, 1 long, 3 short, 1 long); endopod distal article with 4 short and 1 long cuspidate setae on inner distal half, 1 long apical simple seta, 1 short cuspidate seta on outer distal corner. 3.2.2.5. Distribution. NW Pacific, Kuril–Kamchatka abyssal plain, 4830–5418 m. 3.2.2.6. Remarks. There are 15 known species belonging to the genus Bathycuma and five of them inhabit the North West Pacific: B. declinatum Gamô, 1989a (6348–6416), B. granulatum Gamô, 1989a (5349–6416 m), B. longicaudatum Calman, 1912 (about 1000 m in NW Pacific in Gamô, 1967), B. okinawaense Gamô, 1989b (2060–2065 m), B. rotunditectorum Gamô, 1988 (1650 m) (Gamô,1989a, 1989b, 1988). The new species is similar to B. rotunditectorum (only immature male known), but differs from the latter by the following characters: the carapace is serrated on the anterior half (anterior 34 in B. rotunditectorum), the antennal notch is shallower than in B. rotunditectorum; the carapace is significantly convex in the frontal part (smooth bulging carapace in B. rotunditectorum); the mandible has 15 setulate setae (21 in B. rotunditectorum); the maxilliped 3 basis endite is as long as the ischium (in B. rotunditectorum it reaches the carpus). Bathycuma sonne sp. nov. is similar to B. declinatum but differs from this species in the following characters: the carapace is serrated on the anterior half, whereas it is serrated to the hind margin of carapace and shortly interrupted in posterior portion in B. declinatum. The carapace is significantly convex in the frontal part, but uniformly convex on the dorsal side in B. declinatum. The carapace is stout in the new species, but elongate in B. declinatum; the pseudorostrum lacks dorsal spines, while two rows of dorsal spines are present in B. declinatum. Acknowledgments The expedition was undertaken with financial support of the PTJ (German Ministry for Science and Education), Grant 03G0223A to Angelika Brandt. The work was supported by the Russian Foundation of Basis Research (Project 13-04-02144), the Council of the President of the Russian Federation (Project МК2599.2013.4), Otto Schmidt Laboratory Grant (OSL-14-15), Presidium of the Far East Branch of RAS (Project 14-III-В-06-061). The authors are grateful to the crew of the RV “Sonne” for commendable support during the KuramBio expedition and to expedition leader Prof. Angelika Brandt; to Drs. M.V. Malyutina, O.A. Golovan and to Prof. A.V. Chernyshev (IMB FEB RAS, Vladivostok) for the consultation and arrangement of our work. We are grateful to Daniel Roccatagliata and an anonymous reviewer for constructive and fruitful comments. Many thanks to Brigitte Ebbe and Volker Siegel for revising the English text. This is KuramBio publication #5. References Alberico, N.A., Roccatagliata, D., 2008. Diastylis fabrizioi, a new species and brief redescription of D. planifrons Calman, 1912 (Crustacea: Cumacea: Diastylidae) from South America. 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Cumacea (Crustacea) from the Seychelles, Maldives, Sri Lanka (western Indian Ocean), and the Red Sea, with the description of six new species. Beaufortia, 50(12), pp. 197–222. Mühlenhardt-Siegel, U., 2005. Cumacea species (Crustacea: Peracarida) from the deep-sea expedition DIVA-1 with RV 5 “Meteor” to the Angola Basin in July 2000. Families Lampropidae, Bodotriidae. Org. Divers. Evol. 5, 113–130. Mühlenhardt-Siegel U. Some remarks on selected diastylid genera. Part I: Leptostyloides, Divacuma, Austrostylis n. gen. and Pseudoleptostyloides n. gen. (Crustacea, Cumacea, Diastylidae) from the deep South Atlantic //Marine Biodiversity. – С. 1-24. 2014. http://dx.doi.org/10.1007/s12526-014-0259-7. Petrescu, I., 1995. Cumaceans (Crustacea: Peracarida) from the South American coasts collected by the R/V “Vema”. Trav. Mus.´Hist. Nat. “Grigore Antipa” 35, 49–86. Sirenko, B.I. (Ed.), 2013. Check-list of species of free living invertebrates of the Russian Far Eastern Seas, 75. 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