Latreillia williamsi Melo, 1990

Castro, Peter, Williams, Austin B. & Cooper, Lara L., 2003, Revision of the family Latreilliidae Stimpson, 1858 (Crustacea, Decapoda, Brachyura), Zoosystema 25 (4), pp. 601-634 : 625-628

Latreillia williamsi Melo, 1990

( Fig. 5 )

Latreillia williamsi Melo, 1990: 27 , figs 1, 2a, b (synonymy and references). — Melo 1996: 77, unnumbered fig.

TYPE MATERIAL. — Holotype: ♂, GEDIP Project, stn 396, Rio Grande do Sul, Brazil, 155 m (Museu de Zoologia, Universidade de São Paulo, Brazil, MZUSP- 3295). Paratypes: 1 ♂, 2 ♀♀, same as holotype (MZUSP-5492-5494).

TYPE LOCALITY. — Brazil, Rio Grande do Sul, 34°26’S, 51°47’W, 155 m.

MATERIAL EXAMINED. — Brazil. Rio Grande do Sul, 1 ovig. ♀ (USNM 234433), 1 ♂ (USNM 234434). — Rio Grande do Sul, GEDIP, stn 1648, 18.I.1972, 1 ovig. ♀ (MNHN-B 24562).

DISTRIBUTION. — Off the coast of southern Brazil from Rio de Janeiro to the Uruguay border ( Melo 1996: 77). Depth: 130-290 m ( Melo 1996).

DIAGNOSIS. — Dorsal surface of gastric region of carapace usually smooth, rarely topped by spine (see Melo

sal view, left cheliped omitted, most other pereopods missing from specimen.

1990: fig. 1). Gastric region slender, length more than 0.35 carapace length. Hepatic swellings not topped by tubercle or spine. Supraocular spines shorter or longer than ocular peduncles. Meri of third maxillipeds with short tubercle on ventral surface. Abdomen of adult males with somites 4-5 fused (see Melo 1990: fig. 2b); middorsal protuberance on somite 1, acute spine on somite 2. Abdomen of adult females with middorsal protuberance on somite 1, acute spine on each somite 2, 3; somites 4-6 broad and fused with proximal spines laterally near articulation with somite 3. Propodus of each last pair of pereopods (P5) shorter than carpus; dactylus forming subchela when flexed on distal portion of propodus.

Colour: Carapace pale-yellow ( Melo 1990: 30). Pereopods P2-P4 yellow with red rings; P5 yellow without rings, darker in males than in females. Cornea of eyes “wine color”.

REMARKS

Latreillia williamsi is very close to L. metanesa and L. elegans . It is unique among members of the family in that the abdominal somites 4, 5 of males are fused ( Melo 1990: fig. 2b). Only around 9% of the specimens studied by Melo (1990: 30) had a spine on the dorsal surface of the gastric region.

Size

Maximum size: unknown.

Figures

FIG. 5. — Geographical distribution of Latreillia elegans Roux, 1830 (•) and L. williamsi Melo, 1990 (•).