Isocheles sawayai Forest &Saint Laurent, 1968

Nucci, Paulo Ricardo & Melo, Gustavo Augusto Schmidt De, 2015, Hermit crabs from Brazil: Family Diogenidae (Crustacea: Decapoda: Paguroidea), except Paguristes, Zootaxa 3947 (3), pp. 327-346 : 338

Isocheles sawayai Forest &Saint Laurent, 1968

( Figs 3 D, 6F)

Isocheles wurdemanni .— Moreira, 1906: 23, [unnumbered figure].—Rodrigues da Costa, 1962: 1, [unnumbered figure] [non Isocheles wurdemanni Stimpson, 1859: 85 ].

Isocheles sawayai Forest & Saint Laurent, 1968: 107 , figs 62, 63, 68, 69.— Negreiros-Fransozo & Hebling, 1983: 41, figs 1– 12.— Coelho & Ramos-Porto, 1986: 52.— Rieger, 1998: 422.— Melo, 1999: 66, fig. 22.—McLaughlin et al., 2010: 22.

Material examined. Brazil: Alagoas—EO-7, 2 spec. (MZUSP-6818); EO-8, 1 spec. (MZUSP-6845); EO-22, 2 spec. (MZUSP-6848). São Paulo—Ubatuba, Praia Itaguá, 1 spec. (MZUSP-4594); 1 spec. (MZUSP-4592); 9 spec. (MZUSP-4599); 14 spec. (MZUSP-4598); 12 spec. (MZUSP-4597); Ilha de São Sebastião, 2 spec. (MZUSP-4591); Praia Siriúba, 1 spec. (MZUSP-8847); São Sebastião, Praia Araçá, 1 spec. (MZUSP-8850); Praia Barequeçaba, 2 spec. (MZUSP-12998); 7 spec. (MZUSP-8844); 3 spec. (MZUSP-8843); 5 spec. (MZUSP- 8842); Guarujá, Praia Pernambuco, 1 spec. (MZUSP-7289); Santos, 7 spec. (MZUSP-13142); Praia José Menino, 26 spec. (MZUSP-7045); São Vicente, 1 spec. (MZUSP-4595); 15 spec. (MZUSP-600); Itanhaém, Praia Suarão, 1 spec. (MZUSP-7168).

Diagnosis. Shield slightly longer than broad, with transversal granulated saliencies. Rostrum short, triangular, not exceeding lateral projections. Antennular peduncle slightly overreaching cornea. Antennal acicle with 5 or 6 teeth long and acute. Left cheliped slightly stronger than right; dorsal ridge of merus armed with strong spinose teeth distally; dorsolateral margin of carpus with row of strong acute teeth with corneous tip, higher than the width of the base. Dactyls of first ambulatory legs 1.5 times longer than propodus; dorsal face of propodus with 2 parallel rows of spinose corneous teeth, those of the inner row, stronger and more spaced.

Distribution. Western Atlantic—Venezuela and Brazil (from Ceará to Santa Catarina).

Remarks. Isocheles sawayai is very close to I. wurdemanni (not recorded in Brazil), but the two species can be distinguished by several characters: antennal scale of I. sawayai has 5 or 6 long and acute teeth, but in I. wurdemanni , the antennal scale has 7–9 very short and slightly acute teeth; in I. sawayai the dorsolateral margin of the carpus of the left cheliped has a row of strong acute teeth with corneous tips, higher than the width of the base, whereas in I. wurdemanni , this row has teeth with the base wider than the height; the left cheliped has the lateral margin convex in I. wurdemanni and almost completely straight in I. sawayai .

Figures

FIGURE 3. Shield and cephalic region: A, Dardanus fucosus; B, Dardanus insignis; C, Dardanus venosus; D, Isocheles sawayai.