Teramnonotus gordonae ( Monod, 1956 ) Monod, 1956

Santana, William, 2015, A new genus and two new species of hymenosomatid crabs (Crustacea: Brachyura: Hymenosomatidae) from the southwestern Atlantic and eastern Australia, Zootaxa 3905 (1), pp. 91-106 : 93-94

Teramnonotus gordonae ( Monod, 1956) n. gen., n. comb.

( Figs. 4A , 5A , 8A–C )

Elamena (Trigonoplax) gordonae Monod, 1956: 469 , figs. 629–637.

Elamena gordonae — Lucas 1980: 171 [pro parte]; Ng & Chuang 1996: 6 [pro parte]; Yang & Sun 1998: 2; Almeida et al. 2007: 29 [pro parte]; Almeida & Coelho 2008: 197 [pro parte]; Coelho et al. 2008: 18 [pro parte]; Ng et al. 2008: 108.

Material examined. Elamena (Trigonoplax) gordonae Monod, 1956 : ovigerous female holotype cl. 3.1 mm, cw. 2.6 mm, West Africa, between Conakry and Monrovia, Debyser coll., 1–8. iii.1948, 30 – 40 m (MNHN-B25803); Sierra Leone, Trawler Maid Honour, J. Cadenat coll., 1–8.iii.1948, between 8º38'N and 8º42'N, 8–12 m, female paratype (abdomen absent) cl. 2.4 mm, cw. 2.2 mm (MNHN-B25802, currently MNHN-IU-2014-4029).

Diagnosis. Rostrum well detached from the carapace outline, long, outreaching by far the second antennular article, apex sharp. Pterygostomial lobes large, first ending in acute tip, second much smaller but well discernible, followed by strong branchiostegal carina extending posteriorly to level of P3/P4. Subhepatic lobes clearly of distinct sizes, first much larger, lobes visible dorsally. Antennules not visible dorsally when folded. Tuft of setae on metagastric region of carapace small. Cheliped fingers moderately curved, laterally compressed; fingers edentate along cutting margins, not interlocking distally; fixed finger distal end inflated, minutely serrate, denticles rounded. Male unknown.

Remarks. Teramnonotus gordonae ( Monod, 1956) n. gen., n. comb., described by Monod (1956) as Elamena gordonae from two females (one ovigerous) collected between Conakry and Monrovia, and from Sierra Leone, has never been reported from West Africa since its collection in 1948. The male of the species is currently unknown. In T. gordonae , the P2–P5 dactyli end in an acute unguis preceded by two ventral, subdistal spines. Monod (1956: 470, fig. 630) erroneously figured only one ventral, subdistal spine in P5, but his figure 636 of the P5 and his description of the pereiopods are correct: " Péreiopodes grêles, avec au bord supéro-distal du mérus une forte saillie tuberculiforme; dactyles 3-dentés (1 apicale + 2 subapicales internes)" ( Monod 1956: 472, fig. 636). Teramnonotus gordonae (Monod) has been mistakenly recorded as Elamena gordonae from Australia (by Lucas 1980) and from Brazil (by Coelho Filho & Coelho 2002; Almeida et al. 2007; Almeida & Coelho 2008; Coelho et al. 2008). The Australian and the Brazilian specimens actually represent two separate new species herein described.

Yang & Sun (1998) commented on the supposed resemblance between Elamena longidactylis Yang & Sun 1998 , and Teramnonotus gordonae ( Monod, 1956) n. gen., n. comb. (as Elamena gordonae ). Their resemblance, however, is only superficial because in E. longidactylis (as typical for Elamena ), the ocular peduncle is not fused to the carapace and is freely movable, and the female thoracic sternite 8 is not concealed by the carapace in dorsal and posterior views (in contrast to Teramnonotus n. gen., see above). As stated by Yang & Sun (1998), the examined male and female of E. longidactylis also have thinner dactyli with three subterminal teeth on their ventral surface (instead of two in T. gordonae ). Both sexes nevertheless have one anterior prominent pterygostomial lobe followed by a much smaller one (as in T. gordonae ).

Distribution. So far known only from West Africa (between Conakry, Guinea and Monrovia, Liberia and from Sierra Leone), between 8 and 40 meters deep.

Figures

FIGURE 4. A – D, habitus, dorsal view. A, Teramnonotus gordonae (Monod, 1956) n. gen., n. comb., holotype (after Monod 1956: fig. 629). B, Teramnonotus johnlucasi n. gen., n. sp., ovigerous female holotype cl. 2.8 mm, cw. 2.7 mm (AM P. 12208). C, Teramnonotus monodi n. gen., n. sp., ovigerous female paratype cl. 4.3 mm, cw. 3.6 mm (MZUSP 10273). D, Elamena mathoei (Desmarest, 1823), female (ZRC 1994.4235). Scales: A – D, 1 mm.

FIGURE 5. A – D, anteroventral view of the cephalothorax. A, Teramnonotus gordonae (Monod, 1956) n. gen., n. comb., holotype (after Monod 1956: fig. 630 bis). B, Teramnonotus johnlucasi n. gen., n. sp., ovigerous female holotype cl. 2.8 mm, cw. 2.7 mm (AM P. 12208). C, Teramnonotus monodi n. gen., n. sp., ovigerous female paratype cl. 4.3 mm, cw. 3.6 mm (MZUSP 10273). D, Elamena mathoei (Desmarest, 1823), female (ZRC 1994.4235). Arrows indicate the rostrum, which is integrated into the carapace outline in B (rostrum well detached from the carapace outline in C). Scales: A – D, 1 mm.

FIGURE 8. A – C, Teramnonotus gordonae (Monod, 1956) n. gen., n. comb. A, ovigerous female holotype cl. 3.1 mm, cw. 2.6 mm (MNHN-B 25803). B – C, ovigerous female paratype cl. 2.4 mm, cw. 2.2 mm (MNHN-B 25802) (after Monod 1956: figs. 634 and 636). D – F, Teramnonotus johnlucasi n. gen., n. sp., ovigerous female paratype cl. 2.5 mm, cw. 2.4 mm (MZUSP 32909). G – I, Teramnonotus monodi n. gen., n. sp., ovigerous female paratype cl. 4.3 mm, cw. 3.6 mm (MZUSP 10273). A, D, G, right cheliped, lateral view. B, E, H, right P 2, lateral view. C, F, I, left P 5, lateral view. Scales: 1 mm.