Austinixa felipensis (Glassell, 1935)

Theil, Emma Palacios & Felder, Darryl L., 2020, Phylogeny of the genus Austinixa Heard & Manning, 1997, inferred from mitochondrial and nuclear molecular markers, with descriptions of three new species and redescription of Austinixa felipensis (Glassell, 1935) (Decapoda: Brachyura: Pinnotheridae), Zootaxa 4778 (1), pp. 101-134 : 126-129

Austinixa felipensis (Glassell, 1935)

( Figs 10 , 11 )

Pinnixa felipensis Glassell, 1935: 14 .

Pinnixa salvadorensis Bott, 1955: 59 , text fig. 3a–c, pl. 7 fig. 11a, b (fide Heard & Manning 1997: 393).

Material examined. MCZ 9319 , 2 males, cw 8.9 and 9.1 cl 3.6 and 3.5 mm, one ovigerous female, cw 10.2 cl 3.8 mm, one female, cw 9.5 cl 3.8 mm, San Felipe , Baja California, Mexico, 1 Jun 1934, coll. S. A. Glassell ; ULLZ 5558 , 33 males, cw 3.2–13.0 cl 1.6–4.7 mm, San Felipe , Baja California, Mexico, sandy beach with shrimps and thalassinids, 7 Dec 2001, coll. J. Cuesta, R. Robles, F. Mantelatto , DNA voucher; ULLZ 5564 , 7 males, cw 6.7–11.1 cl 2.8–3.9 mm, 5 ovigerous females, cw 8.8–10.7 cl 3.5–3.9 mm, 2 females, cw 8.3 and 9.5 cl 3.4 and 3.6 mm, Las Enramadas , near Cosigüina, Nicaragua, 18 Nov 2001, coll. J. Cuesta, R. Robles, T. Rodríguez , DNA voucher; ULLZ 5565 , 4 juveniles, cw 4.0–4.6 cl 1.9–2.1 mm, 10 males, cw 4.1–9.9 cl 2.1–3.8 mm, 2 ovigerous females, cw 9.1 and 9.8 cl 3.4 and 5.0 mm, 2 females, cw 5.3 and 9.1 cl 2.3 and 3.5 mm, collection data same as previous, DNA voucher .

Size: Males cw 3.8–13.0 mm (n = 50), ovigerous females cw 8.8–10.7 mm (n = 7), females cw 4.4–11.7 mm (n = 44), juveniles cw 4.0– 4.6 mm (n = 4). Female holotype (SDSNH 210) size reported as cw 8.3 cl 3.2 mm ( Glassell 1935a).

Distribution. Known from vicinity of the type locality, San Felipe, Baja California, Mexico and Las Enramadas, Nicaragua.

Diagnosis. Carapace without branchial ridges; males without obvious patch of setae on the posterior region of the carapace, anterior to cardiac ridge; propodus of third walking leg (P4) opposable margin bicarinate; pleonal male telson semiellipsoid, more than twice as wide as long; asymmetric chelipeds, with one chela clearly larger than other, larger cheliped strong, fixed finger short.

Description. (amended from Glassell 1935a: 14) Carapace smooth, 2.0–2.8 times wider than long, with sharp cardiac crest extending entirely across cardiac region, above posterior margin, lacking additional ridges across branchial regions, short setae on lateral angles, lacking patches of setae on posterior carapace, anterior to cardiac ridge. Antennae with 9 segments, third longest ( Fig. 10A, B ). Third maxilliped ischiomerus indistinguishably fused, elongate; 3-segmented palp, nearly as long as ischiomerus; carpus very short; dactylus and propodus elongate, dactylus inserted near base of propodus, reaching clearly beyond distal end of propodus; exopod with angle on non-opposable margin ( Fig. 10C ). Chelipeds of male and female similar, right and left chelipeds asymmetric, both strong, smooth, palm inferior margin setose, gape between fingers densely setose; palm of larger cheliped swollen, with fixed finger strongly shortened, reduced to broad base with serrated surface, dactylus strongly curved to meet fixed finger, ending in serrated surface opposite surface on fixed finger, forming grinding surface; palm of smaller cheliped lighter, with longer fixed finger, slightly deflexed, fixed finger with serrated superior surface, lightly pointed ( Figs 10 D–G, 11D, E). P2–P5 long and slender, relative lengths P4> P3> P2> P5, margins setose, but not densely in P2 and P3, denser and longer on P4 and P5 meri and dactylus posterior margins, P5 dactylus setae reaching distal end, P4 dactylus setae extending about half length of dactylus; dactyli slender, P2 and P3 dactyli slightly curved, P4 and P5 dactyli straight; P4 propodus posterior surface bicarinate ( Fig. 10A , H–K). Male pleon with 6 somites plus telson, none fused, first somite subtrapezoidal, somites 2–6 subrectangular, slightly decreasing in width, telson semiellipsoid, about twice as wide as long ( Fig. 11A ). Female pleon subcircular with 6 somites plus telson, fourth somite widest, somites 3–6 and telson of about same length, somites 1 and 2 each of about half length of third somite ( Fig. 11F ). Male first gonopod as illustrated ( Fig. 8B, C ).

Remarks. The specimens cataloged as MCZ 9319 were collected and identified by Steve A. Glassell as Pinnixa felipensis (now Austinixa felipensis ), and were labelled by him as paratypes. However, he did not indicate this as such in his original description ( Glassell 1935a), and only the female holotype (SDSNH 210) was listed. The use of these topotypic specimens, rather than the holotype only, allowed comparison of not only females but also males to specimens of potential conspecifics and congeners collected more recently. The MCZ specimens were matched to illustrated specimens (ULLZ 5556) that were collected more recently. These recently collected specimens provide gene-sequence quality vouchers, allowing for their further use in molecular phylogenetic studies as well as morphological comparisons.

Figures

FIGURE 8. Austinixa roblesi sp. nov.; A, B, D–G, male paratype, cw 9.0 mm (USNM 1558340); C, H, I, male holotype, cw 9.9 mm (USNM 1558341); both from Dangriga, Belize. A, carapace, chelipeds, and right ambulatory appendages, dorsal; B, carapace frontal region, from anterior; C. third maxilliped, external; D, right chela, internal, setae not shown; E, right pereopod 4, dorsal; F, right pereopod 5, dorsal; G, male pleon; H, left first gonopod tip, pleonal surface; I left first gonopod tip, sternal surface. Scale bars = 1.0 mm.

FIGURE 10. Austinixa felipensis; male, cw 12.3 mm (ULLZ 5556); from San Felipe, Baja California, Mexico. A, carapace, chelipeds, and right ambulatory appendages, dorsal; B, carapace frontal region, from anterior; C. third maxilliped, external; D, right chela, internal; E, right cheliped, external; F, left cheliped internal; G, left cheliped external; H, right pereopod 2, dorsal; I, right pereopod 3, dorsal; J, right pereopod 4, dorsal; K, right pereopod 5, dorsal. Scale bars = 2.0 mm.

FIGURE 11. Austinixa felipensis; A–C, male, cw 12.3 mm (ULLZ 5556); D–F, female cw 10.6 mm, both from San Felipe, Baja California, Mexico. A, male pleon; B, right first gonopod, sternal surface; C, right first gonopod tip, pleonal surface; D, left chela, external; E, left chela, internal. Scale bars = 1.0 mm (A, B, D–F), 0.5 mm (C).