Rev. Biol. Trop. 50(2): 643-647, 2002
www.ucr.ac.cr www.ots.ac.cr www.ots.duke.edu
Distribution and ecological notes on Dynoides
(Isopoda: Sphaeromatidae) in the Mexican Pacific
María del Carmen Espinosa-Pérez and Michel E. Hendrickx
Laboratorio de Invertebrados Bentónicos, Instituto de Ciencias del Mar y Limnología, Unidad Académica Mazatlán,
UNAM. A. P. 811 Mazatlán, Sinaloa, 82000, México. Fax 52 69 82 61 33; e-mail: carmene@ola.icmyl.unam.mx and
michel@mar.icmyl.unam.mx
Received 26-VI-2001.
Corrected 05-II-2002.
Accepted 10-IV-2002.
Abstract: Two species of the genus Dynoides Barnard, 1914 (D. crenulatus Carvacho and Haasmann, 1984; D.
saldanai Carvacho and Haasmann, 1984) not reported since their description were rediscovered during an intensive sampling program in the intertidal and shallow subtidal of the Mexican Pacific. Both species are abundant
in the area and inhabit among the algae Jania adherens Lamouroux, 1816, Amphiroa misakiensis Yendo, 1902,
Chaetomorpha linum Kützing, 1845, and Hypnea pannosa Agardh, 1847 from Nayarit to Oaxaca.
Key words: Isopoda, Dynoides, Mexican Pacific, distribution, fecundity.
Since it was created by Barnard (1914),
several species have been added to the genus
Dynoides. Harrison and Ellis (1991) considered only four species, overlooking the contribution of Carvacho and Haasmann (1984) who
described two new species for the state of
Oaxaca and first recorded the genus for the
entire American Pacific. They also overlooked
seven additional species described between
1980 and 1991. In addition to these species,
another member of this genus was described in
1997 and one species was transferred to
Dynoides. Li (2000) described another species
from Hong Kong, transferred all species of
Clianella to Dynoides and considered that 18
species of the genus are known to date, overlooking D. conchicola (Nishimura, 1976) from
Japan. The 19 species presently included in
Dynoides are: D. serratisinus Barnard, 1914
[South Africa]; D. elegans (Boone, 1923)
[California]; D. barnardi Baker, 1928
[Australia]; D. dentisinus Shen, 1929 [Japan,
Korea, China Sea]; D. amblysinus Pillai, 1954
[India]; D. castroi Loyola and Silva, 1960
[Brazil]; D. conchicola (Nishimura, 1976)
[Japan]; D. brevispina Bruce, 1980 [Japan]; D.
viridis Bruce, 1982 [Australia]; D. crenulatus
Carvacho and Haasmann, 1984 [Mexican
Pacific]; D. saldanai Carvacho and Haasmann,
1984 [Mexican Pacific]; D. spinipodus Kwon
and Kim, 1986 [Korea]; D. brevicornis
Kussakin and Malyutina, 1987 [Eastern
Russia]; D. longisinus Kwon, 1990 [Korea]; D.
hoonsooi Kwon, 1990 [Korea]; D. indicus
Mueller, 1991 [Sri Lanka]; D. harrisoni
Kussakin and Malyutina, 1993 [China Sea]; D.
artocanalis Nunomura, 1997 [Japan]; and D.
daguilarensis Li, 2000 [Hong Kong]. Kensley
and Schotte (2001) cite all these species,
except D. castroi and D. brevicornis (see
Loyola and Silva 1960, Kussakin and
Malyutina 1987) and the species of Clianella
transferred by Li (2000).
Despite of its evident abundance along the
Pacific coast of Mexico, it took 70 years after
Dynoides was described to record a species of
this genus in the area. Indeed, D. crenulatus
and D. saldanai were collected in 1982 from
Puerto Escondido (15º 52.0’ N - 97º 07.0’ W),
Oaxaca, Mexico, and described two years
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REVISTA DE BIOLOGÍA TROPICAL
Fig. 1. Sampling localities of genus Dynoides along the Pacific coast of Mexico. A) D. crenulatus; B) D. saldanai (open
circle, no specimens found; solid circle, specimens found).
after. Up to date, they have been reported only
for their type locality.
During an intensive sampling program (13
localities) of intertidal and shallow water
isopods along the Pacific coast of Mexico, D.
crenulatus and D. saldanai were rediscovered
in several localities, often abundantly.
Abbreviations used in this paper are: St.,
sampling station; IT, intertidal zone; TL, total
length; NS, specimen not sexed; NM, specimen
not measured; M, male; F, female; OF, ovigerous female; EMU-, Reference Collection of
Invertebrates, Unidad Académica Mazatlan,
UNAM, followed by catalog number.
MATERIALS AND METHODS
RESULTS
Specimens were all obtained from a series
of samples in the intertidal and shallow subtidal
(1996 and 1997) in the coastal area comprised
between Los Algodones Bay (27º 58.6’ N 111ºl07.7’ W), north of Guaymas Bay, Sonora,
and San Juan de Alima (18º36.1’ N - 103º
42.1’ W), in the northern part of Michoacan,
Mexico (Fig. 1).
Collecting was done by hand, among
algae, under rocks and in rock crevices and
along sandy beaches. Scuba diving was used in
shallow water. Water temperature (field thermometer) and position (portable GPS) were
registered in every collecting site. Specimens
of algae were preserved and kept for identification. Fecundity of the two species of
Dynoides was estimated in terms of egg numbers related to total body length. The material
collected was deposited in the invertebrates
reference collection of the Unidad Académica
Mazatlán, Instituto de Ciencias del Mar y
Limnología, UNAM (EMU-).
Dynoides Barnard, 1914
Dynoides crenulatus Carvacho and
Haasmann, 1984
Dynoides crenulatus Carvacho and Haasmann,
1984: 23-27, Figs. 5 - 6.
Examined material: Punta Raza (21º
02.6’ N - 105º 19.4’ W), Nayarit, 11/IV/1996,
IT, 6 M (TL 2.6 - 3.6 mm), 18 F (TL 1.9 - 3.3
mm), 2 OF (TL 3.3 mm) and 22 additional
specimens (NS, NM) (EMU-4407). Same
locality, 11/IV/1996, IT, 2 M (TL 4.1 mm), 2 F
(TL 2.4 mm), manual (EMU-4638). Same
locality, 11/IV/1996, IT, 5 M (TL 3.1 - 4.4
mm), 20 F (TL 2.4 - 3.2 mm), 3 OF (TL 2.9 3.4 mm) and 33 additional specimens (NS,
NM) (EMU-4687). Los Arcos (20º 32.5’ N 105º 18.4’ W), Jalisco, 12/IV/1996, IT, 9 M
(TL 3.2 - 4.4 mm), 14 F (TL 2.6 - 3.3 mm), 2
OF (TL 3.8 mm) and 23 additional specimens
INTERNATIONAL JOURNAL OF TROPICAL BIOLOGY AND CONSERVATION
645
females of 1.9 to 3.3 mm, and ovigerous
females of 2.9 to 3.8 mm (TL). The analysis of
fecundity indicates an increase of egg number
(from 24 to 39 eggs) with total body length
(Fig. 2A).
Dynoides saldanai
Carvacho and Haasmann, 1984
Dynoides saldanai Carvacho and Haasmann,
1984: 27-31, Figs. 6 - 8.
Fig. 2. Relation between total body length and number of
eggs for A) Dynoides crenulatus and B) Dynoides saldanai.
(NS, NM) (EMU-4639). Bahía Tenacatita (19º
15.9’ N - 104º 47.9’ W), Jalisco, 4/XI/1996, IT,
2 M (TL 3.1 - 3.5 mm), 2 F (TL 3.2 mm), 1 OF
(TL 3.1 mm) and 3 additional specimens (NS,
NM) (EMU-4736).
Previously known localities: Puerto
Escondido, Oaxaca, Mexico (type locality).
Geographic distribution: From Punta
Raza, Nayarit (SE Gulf of California) to Puerto
Escondido, Oaxaca, Mexico. Although similar
habitats were sampled in ten additional localities, no specimens of D. crenulatus were found
(Fig. 1A).
Habitat: Lower midintertidal zone,
among algae and cirripeds on rocky beaches
exposed to waves (Carvacho and Haasmann
1984). Material examined was collected in the
rocky intertidal, associated to the algae Jania
adherens, Amphiroa misakiensis, Chaetomorpha linum and Hypnea pannosa; water temperature varied from 25.5 to 29.0ºC.
Size and fecundity: Maximum size (TL)
is 4.75 mm for males and 4.0 mm for females
(Carvacho and Haasmann 1984). Material
examined contains males of 2.6 to 4.4 mm,
Examined material: Punta Raza (21º
02.6’ N - 105º 19.4’ W), Nayarit, 11/IV/1996, IT,
5 M (TL 2.5 - 3.5 mm), 16 F (TL 2.4 - 3.4 mm)
and 3 OF (TL 2.8 - 3.1 mm) (EMU-4686).
Same locality, 11/IV/1996, IT, 19 M (TL 2.8 4.8 mm), 110 F (TL 1.2 - 3.8 mm), 39 OF (TL
2.3 - 3.5 mm) (EMU-4668). Same locality,
11/IV/1996, IT, 2 M (TL 4.6 - 5.0 mm), 119 F
(TL 1.2 - 3.5 mm), 5 OF (TL 2.8 - 3.8 mm) and
43 additional specimens (NS, NM) (EMU4669). Same locality, 11/IV/1996, IT, 10 M
(TL 3.4 - 4.7 mm), 100 F (TL 1.3 - 4.0 mm), 16
OF (TL 2.6 - 3.4 mm) and 22 additional specimens (NS, NM) (EMU-4670). Same locality,
11/IV/1996, 3 m, 1 M (TL 2.9 mm), skin diving (EMU-4671). Same locality, 11/IV/1996,
IT, 1 M (TL 5.6 mm) and 13 additional specimens (NS, NM) (EMU-4732). Same locality,
11/IV/1996, IT, 6 M (TL 2.8 - 4.3 mm), 15 F
(TL 1.9 - 2.8 mm) and 6 additional specimens
(NS, NM) (EMU-4733). Sayulita (20º 52.3’ N
- 105º 28.0’ W), Nayarit, 10/IV/1996, 3 m, 1 F
(TL 1.6 mm), skin diving (EMU-4672). Same
locality, 10/IV/1996, 3 m, 1 F (TL 3.1 mm)
(EMU-4673). Los Arcos (20º 32.5’ N - 105º
18.4’ W), Jalisco, 12/IV/1996, IT, 5 M (TL 2.5
- 3.5 mm), 31 F (TL 2.4 - 3.4 mm), 1 OF (TL
2.8 - 3.1 mm) and 26 additional specimens
(NS, NM) (EMU-4674). Manzanillo Bay, El
Arrecife (19º 06.0’lNl-l104º 24.1’lW),lColima,
6/XI/1996, 3 m, 37 M (TL 3.1 - 4.0 mm), 39 F
(TL 2.4 - 2.9 mm) and 78 additional specimens
(NS, NM), skin diving (EMU-4729A). Same
locality, 6/XI/1996, 3 m, 14 M (TL 2.1 3.8 mm), 34 F (TL 2.3 - 3.7 mm), 3 OF
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REVISTA DE BIOLOGÍA TROPICAL
(TL 2.6l- 2.9 mm) and 50 additional specimens
(NS, NM), skin diving (EMU-4729B). Same
locality, 6/XI/1996, 3 m, 27 M (TL 2.3 4.1lmm), 56 F (TL 2.2 - 3.5 mm) and 85
additional specimens (NS, NM), skin diving
(EMU-4730). Same locality, 6/XI/1996, 3 m,
4 M (TL 3.4 - 4.6 mm), 47 F (TL 1.9 2.9lmm) and 55 additional specimens (NS,
NM), skin diving (EMU-4731A). Same
locality, 6/XI/1996, 3 m, 7 M (TL 3.2 4.7lmm), 99 F (TL 2.5 - 4.3 mm) and 50
additional specimens (NS, NM), skin diving
(EMU-4731B). San Juan de Alima (18º
36.1’lN - 103º 42.1’ W), Michoacan,
5/XI/1996, IT, 1 M (TL 3.4 mm), 7 F (TL 2.2 3.1 mm) and 5 additional specimens (NS, NM)
(EMU-4734A). Same locality, 5/XI/1996, IT,
1lM (TL 3.7 mm), 14 F (TL 2.2 - 3.4 mm) and
12 additional specimens (NS, NM) (EMU4734B). Same locality, 5/XI/1996, IT, 4 M (TL
3.4 - 4.6 mm), 18 F (TL 2.5 - 3.8 mm) and 15
additional specimens (NS, NM) (EMU4735A). Same locality, 5/XI/1996, IT, 3 M (TL
3.2 - 3.8 mm), 19 F (TL 2.4 - 3.4 mm), 2 OF
(TL 2.8 - 3.2 mm) and 6 additional specimens
(NS, NM) (EMU-4735B).
Previously known localities: Masunte
Beach (type locality) and Puerto Escondido,
Oaxaca, Mexico.
Geographic distribution: From Punta
Raza, Nayarit (SE Gulf of California) to Puerto
Escondido, Oaxaca, Mexico. No specimens of
D. saldanai were found in the other nine sampling localities (Fig. 1B).
Habitat: Lower midintertidal zone,
among algae on rocky beaches exposed to
waves (Carvacho and Haasmann 1984).
Material examined was collected in the rocky
intertidal to a depth of 3 m, associated to the
algae J. adherens, A. misakiensis, C. linum and
H. pannosa; water temperature varied from
25.0 to 29.0ºC.
Size and fecundity: Male holotype,
4.45lmm (TL); female allotype, 3.0 mm (TL)
(Carvacho and Haasmann 1984). Material
examined contains males of 2.1 to 4.8 mm,
females of 1.2 to 4.3 mm, and ovigerous
females of 2.3 to 3.5 mm (TL). The analysis of
fecundity, in terms of number of eggs (from
nine to 37 eggs), indicates an increase of egg
number with total body length (Fig. 2B).
ACKNOWLEDGMENTS
The authors are grateful to the CONABIO
(Comisión Nacional para el Estudio y Uso de
la Biodiversidad, México) for supporting our
study on the isopod fauna of the Pacific coast
of Mexico (Project CONABIO H-170). We
thank the people who participate in this study:
José Salgado-Barragán, Marcelo García
Guerrero and Manuel Ayon Parente during
field work, and Germán Ramírez Reséndiz
with computer programs.
RESUMEN
Durante un programa intensivo de muestreo en la zona intermareal y submareal somera del Pacífico mexicano
se redescubrieron dos especies del género Dynoides Barnard, 1914 (D. crenulatus Carvacho y Haasmann, 1984; D.
saldanai Carvacho y Haasmann, 1984), no registradas desde su descripción. Ambas especies son abundantes en el
área y habitan entre las algas Jania adherens Lamouroux,
1816, Amphiroa misakiensis Yendo, 1902, Chaetomorpha
linum Kützing, 1845 e Hypnea pannosa Agardh, 1847 desde Nayarit hasta Oaxaca.
REFERENCES
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of South Africa. 3. Additions to the marine Isopoda,
with notes on some previously incompletely known
species. Ann. S. Afr. Mus. 10: 325-442.
Carvacho, A. & Y. Haasmann. 1984. Isópodos litorales de
Oaxaca, Pacífico mexicano. Cah. Biol. Mar. 25: 15-32.
Harrison, K. & J.P. Ellis. 1991. The genera of the
Sphaeromatidae (Crustacea: Isopoda): A key and distribution list. Invertebr. Taxon. 5: 915-952.
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rakoobraznye (Crustacea, Isopoda) litorali Zaliva Petra
Velikogo, p. 47-67. In V.V. Gul’bin (ed.). Issledovaniya
litorali Dal’nevostochnogo morskoga zapovednika i
sopredel’nykh raionov. DVO AN SSR, Vladivostok.
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Marine Reserve, Hong Kong. Rec. Aus. Mus. 52:
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INTERNET REFERENCES
Kensley, B. & M. Schotte. 2001. World list of marine,
freshwater and terrestrial isopods crustaceans.
(http://www.nmnh.si.edu/iz/isopod).