Mecataleptodius parvulus ( Fabricius, 1793 ), gen., 2022

TAVARES, MARCOS & MENDONÇA, JOEL BRAGA DE JR., 2022, Brachyuran crabs (Crustacea, Decapoda) from the remote oceanic Archipelago Trindade and Martin Vaz, South Atlantic Ocean, Zootaxa 5146 (1), pp. 1-129 : 65-68

Mecataleptodius parvulus ( Fabricius, 1793) , gen. nov., comb. nov.

( Figs. 34A, B , 35D )

Cancer parvulus Fabricius, 1793: 451 [Type locality: “Americae meridionalis insulis”].

Trindade specimens. 1 male, 4 females ( MZUSP 39579 ), Brazil, off Espírito Santo, Trindade Island , Parcel das Tartarugas, 20º31’01.3”S, 29º17’56.9”W, J.B. Mendonça coll., 11.vii.2012, 14.5 m . 2 males ( MZUSP 33830 ) , 1 male, 1 juvenile female ( MZUSP 41069 ), ibidem, Praia dos Andradas , 20º30’45.7”S, 29º18’21.9”W, J.B. Mendonça coll., 21.vii.2013, rocky tide pool . 1 male, 1 juvenile female ( MZUSP 40848 ), ibidem, 20º30’37.6”S, 29º18’28.1”W, J.B. Mendonça coll., 20.xi.2017, rocky tide pool . 1 female ( MZUSP 41284 ), ibidem, 20º31’29.8”S, 29º19’52.0”W, J.B. Mendonça coll., 2.vii.2016, at night, rocky tide pool . 4 males, 5 females ( MZUSP 41286 ), ibidem, 20º30’34.5”S, 29º20’29.5”W, J.B. Mendonça coll., 2.xi.2014, at night, rocky tide pool . 1 male, 1 female ( MZUSP 41009 ), ibidem, 20º29’53.9”S, 29º19’24.1”W, J.B. Mendonça coll., 12.iv.2014, rocky coast, tide pool . 5 males, 2 females ( MZUSP 41285 ), ibidem, Enseada dos Portugueses, Farol , 20º29’52.3”S, 29º19’15.6’’W, J.B. Mendonça coll., 22.iv.2014, 13.7 m . 1 male ( MZUSP 40837 ), ibidem, 20º30’25.20”S, 29º18’48.32”W, J.B. Mendonça coll., 19.xi.2017, under stones, tide pool . 1 male ( MZUSP 40743 ), ibidem, Ponta Norte, Crista do Galo , 20º29’22.1”S, 29º20’03.1”W, J.B. Mendonça coll., 17.vi.2012, tide pool . 1 male, 1 ovigerous female ( MZUSP 40933 ), ibidem, 20º29’22.22”S, 29º20’02.87”W, J.B. Mendonça coll. 14.ii.2019, tide pool, 2.5 m . 5 males, 2 females ( MZUSP 40829 ), ibidem, Praia do M, 20º30’50.71”S, 29º20’21.91”W, J.B. Mendonça coll., 13.ii.2019, tide pool, 0.5 m .

Size of largest male: cl 7.9 mm, cw 12.9 mm; largest female: cl 7.9 mm, cw 12.1 mm.

Comparative material examined. Cataleptodius floridanus: Belize: 3 males (USNM 221912), Caribbean Coral Reef Ecosystems Expedition, South Water Cay, 16º49’41.9”N, 88º04’32.9”W, 31.x.1988, back reef. Curaçao: 1 female ( USNM 17812 ), 12°N, 69°W, U. S. Fish Commission, R/V “ Albatross ”, 10.ii.1884, shore. Brazil: 1 male, 1 female ( MZUSP 9937 ), Paraíba, Cabo Branco, Ponta do Seixas, M.D. Rodrigues coll., 8.ii.1979 . Mecataleptodius olsoni gen. nov., comb. nov.: holotype male, cl 5 mm, cw 7.8 mm ( USNM 221887 ), Ascension Island, North English Bay , R.B. Manning coll., stn ASC-5, 19.v.1971 . 5 males, 8 females paratypes (4 ovigerous) ( USNM 252272 ), ibidem, North East Bay , R.B. Manning coll., 19.v.1971 , tide pools. Mecataleptodius parvulus gen. nov., comb. nov.: Caribbean Sea: 2 males, 2 ovigerous females ( USNM 75028 ), Barbados, W. Schmitt coll., stn 64, 21.iv.1937 [M.J. Rathbun det.]. Brazil: Fernando de Noronha Archipelago : 2 females ( MZUSP 7235 ), Boldr, S.A. Rodrigues coll., 1.xi.1985 . 1 female ( MZUSP 9281 ), ibidem, Ponta Air France, P.S. Young coll., 2.xii.1986 .

Distribution. Bermuda, Florida, Gulf of Mexico, Antilles, Venezuela, and Brazil (Fernando de Noronha, Rocas Atoll?, Trindade and São Paulo?) ( Moreira 1920; Melo 1996; 1998; Alves et al. 2008; Barros-Alves et al. 2013; Tavares et al. 2017; Mantelatto et al. 2020).

Mecataleptodius parvulus gen. nov., comb. nov. was first recorded from Trindade by Moreira (1920) as Xanthodius parvulus , and to the best of our knowledge no further specimens have been recorded from there since. Its presence in Trindade is here confirmed. The occurrence of M. parvulus gen. nov., comb. nov. in Fernando de Noronha has been well documented ( Moreira 1920; Melo 1996; Alves et al. 2008. See also above under comparative material), whereas apparently there is no voucher material to support its record from the Rocas Atoll. Coelho & Ramos (1972) listed Xanthodius americanus from Rocas and Trindade without further specifics ( Tavares et al. 2017: 171, tab. 1); while their record probably refers to M. parvulus gen. nov., comb. nov., there is no voucher specimen available to allow confirmation.

Barros-Alves et al. (2013) described the first stage zoea of? C. parvulus [sic] based on larvae hatched from a female captured in Vitória Island, São Paulo. That female has not been located for examination. On the other hand, the previous records of M. parvulus gen. nov., comb. nov., 1 juvenile female, cl 4.2 mm, cw 7 mm, MZUSP 16707 from Vitória Island, off coast of São Sebastião, São Paulo ( Alves et al. 2006, as Xanthodius parvulus ; 2012b: fig. 4D, as Cataleptodius parvulus ) evidently does not correspond to this species.

Ecological notes. Mecataleptodius parvulus gen. nov., comb. nov. has been reported to occur under rocks and tide pools ( Melo 1996) as well as in sand-slimy and sand-muddy bottoms ( Alves et al. 2008). In Trindade, this species was found under rocks on sand bottom, rocky tide pool and crevices, between the tide mark to depths of 14.5 m. The female MZUSP 40933 was ovigerous already at cl 4.1 mm, cw 6.5 mm.

Remarks. The Trindade specimens are distinctly smaller than its conspecific Caribbean counterparts and have the regions of the carapace weakly defined, which was also noted by Moreira (1920). The largest and smallest specimens examined by Moreira were cl 8.5 mm and cw 11.5 mm, and cl 4 mm and cw 6 mm, respectively. The Trindade specimens additionally differ from their conspecific Caribbean counterparts in having much less areolated carapace, anterolateral teeth lower and ill defined, and chelipeds much smoother and remarkably less dimpled. The female MZUSP 41284 has the carapace regions well defined and smooth chelipeds. The first male gonopod of the male MZUSP 41069 ( Fig. 35D ) fully agree with that of the male USNM 75028.

Mecataleptodius parvulus gen. nov., comb. nov. superficially resembles M. olsoni gen. nov., comb. nov., a species endemic to Ascension, in the carapace regions and anterolateral teeth weakly defined. However, M. parvulus gen. nov., comb. nov. differs by having the front of the carapace without a distinct double-edge (present in M. olsoni gen. nov., comb. nov.), smoother chelipeds (much more areolated in M. olsoni gen. nov., comb. nov.) (Fig. 34A–E) and the lower border of the apical projection of the first gonopod bordered with several projections (projections absent in M. olsoni gen. nov., comb. nov.) ( Fig. 35D, E ).

Figures

FIGURE 34. A, B, Mecataleptodius parvulus (Fabricius, 1793), gen. nov., comb. nov., male, cl 6.5 mm, cw 10 mm (MZUSP 40848). C–E, Mecataleptodius olsoni (Manning & Chace, 1990), gen. nov., comb. nov., holotype male, cl 5 mm, cw 7.8 mm (USNM 221887). Habitus, dorsal (A, C) and ventral (B) aspects. D, Anterior view of frontorbital region. E, Right cheliped, lateral view. Photographs (A, B) by A. Pol.

FIGURE 35. A–E, First male gonopods. A–C, Cataleptodius floridanus (Gibbes, 1850). A, B, Male, cl 17 mm, cw 27 mm (MZUSP 9937). C, Male from Tortugas, Florida, cl 7 mm, cw 11 mm (after Monod 1956: 293, fig. 356, as Xantho floridana, reproduced by Guinot 1968: 707, fig. 23, as Cataleptodius floridanus). D, Mecataleptodius parvulus (Fabricius, 1793), gen. nov., comb. nov., male, cl 7.6 mm, cw 12 mm (MZUSP 41069). E, Mecataleptodius olsoni (Manning & Chace, 1990), gen. nov., comb. nov., holotype male, cl 5 mm, cw 7.8 mm (USNM 221887) (after Manning & Chace 1990: 55, fig. 35g). Scales: A, 0.5 mm. B, D, 0.1 mm. C, 1 mm.