The family Cletodidae T. Scott, 1905 is a benthic harpacticoid taxon with about 150 species in 38 genera (George 2020, George 2021, Walter and Boxshall 2022), including species of the Ceratonotus-group sensu Conroy-Dalton, 2001 formerly placed in Ancorabolinae Sars, 1909 (George 2020).

Por (1986) in his review of the family Cletodidae transferred some genera of this family to a new sub-family of Canthocamptidae: Hemimesochrinae, as well as provisionally placed the genus Cletocamptus in the "Canthocamptidae incertae sedis". Later on, Gee (1999), sharing the Por's (1986) opinion, provisionally included the genus Cletocamptus in the family Canthocamptidae incertae sedis, suggestings as well that this genus "must be removed to a new family which will brobably prove to be a sister family to the Cletodidae".

More recently, Mielke (2000) confirmed that "The situation of the genus Cletocamptus is complex and in some respects inconsistent..... This uncertainty is due to the conjecture that the two families, Canthocamptidae and Cletodidae, appear to be poly- or para-phyletic assemblages".

The genus Pontocletodes Apostolov, 1980 was not defined by Por (1986) and it is provisionally assigned to Cletodidae. Bodin (1997) reported the same genus as "incertae sedis", adding some new genera to the family Cletodidae.

"Uncovering the systematics of Copepoda Harpacticoida, the second-most abundant component of the meiobenthos after Nematoda, is of major importance for any further research dedicated especially to ecological and biogeographical approaches. Based on the evolution of the podogennontan first swimming leg, a new phylogenetic concept of the Ancorabolidae Sars and Cletodidae T. Scott sensu Por (Copepoda, Harpacticoida) is presented, using morphological characteristics. It confirms the polyphyletic status of the Ancorabolidae and its subfamily Ancorabolinae Sars and the paraphyletic status of the subfamily Laophontodinae Lang. Moreover, it clarifies the phylogenetic relationships of the so far assigned memb ers of the family.

An exhaustive phylogenetic analysis was undertaken using 150 morphological characters, resulting in the establishment of a now well-justified monophylum Ancorabolidae. In that context, the Ancorabolus-lineage sensu Conroy-Dalton and Huys is elevated to sub-family rank. Furthermore, the membership of Ancorabolina George in a rearranged monophylum Laophontodinae is confirmed. Conversely, the Ceratonotus-group sensu Conroy-Dalton is transferred from the hitherto Ancorabolinae to the Cletodidae. Within these, the Ceratonotus-group and its hypothesised sister-group Cletodes Brady are combined to form a monophyletic subfamily Cletodinae T. Scott, subfam. nov. Consequently, it was necessary to restructure the Ancorabolidae, Ancorabolinae and Laophontodinae and extend the Cletodidae to include the displacement and exclusion of certain taxa. Moreover, comparison of the Ancorabolidae, Cletodidae, Laophontoidea and other Podogennonta shows that the Ancorabolidae and Cletodidae form sister-groups in a monophylum Cletodoidea Bowman and Abele, which similarly has a sister-group-relationship with the Laophontoidea T. Scott. " (from George, 2020

"Currently the Ceratonotus group sensu Conroy-Dalton (2001) comprises nine genera: Arthuricornua Conroy-Dalton, 2001, Ceratonotus Sars, 1909, Dendropsyllus Conroy-Dalton, 2003, Dimorphipodia Lee & Huys, 2019, Dorsiceratus Drzycimski, 1967, Echinopsyllus Sars, 1909, Polyascophorus George, 1998, Pseudechinopsyllus George, 2006, and Touphapleura Conroy-Dalton, 2001 (Sars1909; Drzycimski 1967; George 1998, 2006a; Conroy-Dalton 2001; Conroy-Dalton 2003a; Lee & Huys 2019)" (from George, 2021)

Pending a definitive review of the family, the genus Cletocamptus is herein provisonally placed in the Cletodidae sensu Scott, 1904; Por, 1986, which presently should include the following other genera: Acrenhydrosoma, Cletodes, Enhydrosoma, Enhydrosomella, Kollerua, Limnocletodes, Stylicletodes [Monocletodes Lang], Barbaracletodes, Australonannopus, Scintis, Strongylacron, Schizacron, Monocletodes, Intercletodes, Dyacrenhydrosoma, Paracrenhydrosoma Triathrix, Sphingothrix, Neoacrenhydrosoma (Por, 1986, Fiers, 1987; Bodin, 1997; Gee, 1998,1999) and Spinapecruris Gee, 2001.

Revised Keys to Species of Cletodes

"Enhydrosoma Boeck, 1872 is one of the biggest genera in the family Cletodidae T. Scott, 1905. Gee [1] partially reviewed the taxonomic characters of the genus Enhydrosoma in the Cletodidae. Enhydrosoma species have been moved to other genera or newly erected genera within Cletodidae on several occasions [1–5]. The genus has diverse congeners, more than 53 valid species and several authors suggests a necessity for the revision of the genus since it is polyphyletic in nature" (from: Park et al., 2020)

The genus Enhydrosoma has been a taxonomic debate since its erection by Boeck (1873). Various attempts (Sars, 1909; Lang, 1936; 1948; 1965; Thistle, 1980; Gee, 1994; Kim et al., 2014; Karanovic et al., 2015) had been taken to construct a monophyletic group but this task still could not be accomplished because of the insufficient descriptions and figures that lack important characters such as the form and setation of the mouthparts, and even periopods on some occasions (Sonmez et al,. 2018)

* species inquirenda (Lang, 1965; Por et al., 1984)

** recently moved to the genus Spinapecruris Gee, 2001 (Gee, 2001)

In a paper on the genus Enhydrosoma, Jakobi (1955) describcd several new species. However they are so superficially described that in Lang's opinion (1965) they should be simply ignored. Fiers (1996b) considered some of them as junior synonyms of E. lacunae

Cletocamptinae Gomes & Rivera, 2022

CLETOCAMPTUS Schmankewitch, 1875

Synonymised names Godetella Delachaux, 1918 (synonym) Marshia Herrick, 1895 (synonym) Regis Labbé, 1927 (synonym) Sinocamptus Shen & Sung, 1963 (synonym) Wolterstorffia Schmeil, 1894 (synonym)

"The genus Cletocamptus is considered cosmopolitan (Suárez-Morales et al, 2013) and its species occur in a wide salinity range, being reported in estuaries, costal and beach lagoons but few species are found in full freshwater" (from Fuentes-Reines et al., 2015).

The systematic status of the genus is still controversial. Several authors (Por, 1968; Bodin, 1997; Mielke, 2000, 2001; Gomez et al., 2007) include it in Canthocamptidae incertae sedis sensu Por, 1986. Pending a definitive review of the above family, the genus Cletocamptus is herein provisonally placed in the Cletodidae sensu Scott, 1904.

At present the valid species within Cletocamptus are C. retrogressus Schmankewitsch, 1875, C. confluens (Schmeil, 1894), C. albuquerquensis (Herrick, 1894), C. trichotus Kiefer, 1929, C. feei (Shen, 1956), C. affinis Kiefer, 1957, C. gravihiatus (Shen and Sung, 1963), C. helobius Fleeger, 1980, C. merbokensis Gee, 1999, C. axi Mielke, 2000, C. schmidti Mielke, 2000, C. deborahdexterae Gomez, Fleeger, Rocha-Olivares and Foltz, 2004, C. stimpsoni Gomez, Fleeger, Rocha-Olivares and Foltz, 2004, C. gabrieli Loffler, 1961, C. sinaloensis Gomez, Fleeger, Rocha- Olivares and Foltz, 2004, C. bicolor (Wilson, 1932), C. xenuus Por, 1968 , C. kummieri (Delachaux,1917), C. stimpsoni Gomez, Fleeger, Rocha Oliovarez & Faltz, 2003, C. fourchensis Gomez, Fleeger, Rocha-Olivares and Foltz, 2004, C. cecsurirensis Gomez, Scheihing & La Barca, 2007. C. mongolicus (Sterba, 1967), C. levis Gomez, 2005, C. nudus Gomez, 2005 , C. samariensis Fuentes-Reines et al., 2015.

Gomez et al. (2004) considered as species inquirendae some species within the genus and they also considered as doubtful some records of C. deitersi. Additional doubtful records of C. deitersi are those of Brehm (1936, 1965), Chappuis (1936), Ringuelet (1958a, 1958b, 1960, 1962), Ringuelet et al. (1965), Oliveira and Miranda (1971), Apostolov (1984), Ruber et al. (1994), and Loftus and Reid (2000).

Recently moved to Canthocamptidae Brady, 1880, subfamily Canthocamptinae Brady, 1880 (Walter, T.C.; Boxshall, G. (2021). World of Copepods Database. Cletocamptus Schmankevitsch, 1875. Accessed through: World Register of Marine Species at: http://www.marinespecies.org)

* Cletocamptus confluens, according to its variability and widespread occurrence, could be considered an "assemblage of barely discernible species" (Mielke, 2000). For the same reason, the subspecies Cletocamptus confluens cyrenaica Brehm, 1908 and Cletocamptus confluens meridionalis Kiefer, 1929 are questionable.

**taxa inquirenda, according to Wells (2007)

Map of the distribution of Cletocamptus confluens (after Mielke, 2000 modif.)

The species Cletocamptus deitersi and Cletocamptus retrogressus are geographically widspread, and morphologically and ecologically variable thus implying the existence of morphologically indistinguishable sibling species (Mielke, 2001).

| Key to the species of Cletocamptus |

STRONGYLACRON Gee & Huys, 1996

"The harpacticoid copepod genus Strongylacron Gee & Huys, 1996 belonging to the family Cletodidae T. Scott, 1904 was established by Gee and Huys (1996) as a part of an effort to resolve the relationship among members of Enhydrosoma Boeck, 1873. The latter genus was recognized as a heterogeneous group by Fiers (1987) and Mielke (1990). After the studies of Lang (1936, 1948), this genus was distinguished from Cletodes Brady, 1972 by subtle morphological characteristics such as the form and setation of the distal segment on legs 3 and 4 (Gee 1994, 2001; Gee and Huys 1996). In the revision of Enhydrosoma, Gee (1994) first proposed the buchholtzi-species group representing differences from others in the rostrum, antenna, maxillule and male P3 endopod. In addition, he suggested that this group should be removed from Enhydrosoma. Thereafter, the buchholtzi-species group was revised and the following three genera were established: Schizacron Gee & Huys, 1996, Spinapecruris Gee, 2001, and Strongylacron Gee & Huys, 1996 (Gee 1994, 2001; Gee and Huys 1996). Strongylacron is a monospecific genus containing Strongylacron buchholtzi (Boeck, 1873) (Walter and Boxshall 2016)" (Kim et al., 2016),