Automate spinosa, Wang, Yan-Rong & Sha, Zhong-Li, 2017

Wang, Yan-Rong & Sha, Zhong-Li, 2017, Description of two new species of the genus Automate De Man, 1888 (Crustacea: Decapoda: Caridea) from the South China Sea, Zootaxa 4238 (1) : -

Automate spinosa sp. nov.

( Figs. 4–5 )

Material examined. Holotype, MBM 159184, 1 ovigerous female (CL 4.9mm, TL 14.1mm), Sanya Gulf, 2 December 1997. Paratype, MBM 270172, 1 male (CL 3.1mm, TL 9.5mm), Beibu Gulf, depth 42m, Hôñg Coll., 24 October 1962. MBM 107686, 2 ovigerous female (CL 4.7mm, TL 13.6mm), Sanya Gulf, 2 April 1958.

Description. Carapace glabrous. Frontal region of carapace ( Fig. 4 A–C) deeply recessed posterior to eyes, nearly straight mesially, without rostrum or median lobe; rostral carina and orbital hoods absent. Eye-stalls exposed dorsally and laterally, cornea developed. Pterygostomian angle ( Figs. 4 A, C, 5K) rounded, continuous with branchiostegal; cardiac notch conspicuous.

Antennular peduncle ( Figs. 4 B, 5K) slender; dorso-mesial margin of first segment with 1–2 small, somewhat anteriorly curved spines; with second segment much longer than visible part of first; stylocerite acute, not reaching distal end of first segment of antennular peduncle. Antenna ( Fig. 4 C) with basicerite bearing ventro-lateral tooth; carpocerite slender, just reaching distal end of antennular peduncle; scaphocerite oval, overreaching middle of second segment of antennular peduncle, lateral margin slightly concave, disto-lateral tooth distinctly beyond anterior margin of blade.

Mandible ( Fig. 5 E) with two-segmented palp; incisor process bearing distally 5 blunt, strong, large teeth and one small, sub-acute tooth; molar process well developed. Maxillule ( Fig. 5 F) with two endites, distal endite with numerous large spine-like setae on inner margin; palp bilobed, upper lobe rounded, with one robust seta, lower lobe with two robust seta. Maxilla ( Fig. 5 G) with slender tapering palp bearing one robust seta on tip; distal endite bilobed, densely setose medially; proximal endite with single lobe, lanceolate, distally with setae; scaphognathite well developed. First maxilliped ( Fig. 5 H) with two-segmented palp; distal endite with medial margin slightly concave, with dense setae; proximal endite small; exopod with well-developed flagellum, distally with long setae. Second maxilliped ( Fig. 5 I) with dactylar segment narrow, medial margin with moderately short spiniform setae; propodal segment slightly elongate rounded distally, distomedial border with long setae; carpus short; ischiomerus short, basis long, stout; coxa with large epipod; exopod well developed, with long flagellum, distally with long setae. Third maxilliped ( Fig. 5 J) slender; arthrobranch ( Fig. 4 N) normally developed; coxa with hook-like epipod, exopod slightly not reaching to mid-length of antepenultimate segment; antepenultimate segment near as long as ultimate segment, dorsal margin with several moderately short setae; penultimate segment about 1/3 length of antepenultimate segment; ventral margin of ultimate segment setose; superior margin armed with transverse rows of moderately small, but strong spines, distally with one small, strong spine; basipodite with epipod hook-shaped.

First pereiopod ( Figs. 4 D–G, 5L) robust and strongly asymmetrical in shape and size. Major cheliped ( Fig. 4 D, E) with ischium bearing only setae on superior distal margin; merus about three times as long as wide at base, slightly produced near distal; carpus vase-shaped; palm rectangular, lower margin bearing moderately dense, long setae; fingers ( Fig. 4 G, F) distinctly shorter than palm, bearing one or two large teeth on cutting edge, inner side of pollex bearing thin, short setae. Minor cheliped ( Fig. 5 L) with ischium, merus and carpus similar to that of major cheliped; merus about three times as long as wide at middle; carpus about 1/2 length of chela; fingers slightly shorter than palm; tip of fingers crossing when closed.

Second pereiopod ( Fig. 5 M) slender; carpus five-segmented, second segment longer other segments, ratio of segments from proximal to distal approximately equal to 0.4: 1.3: 0.7: 0.5: 0.5. Third pereiopod ( Fig. 4 H, I) moderately stout, ischium unarmed; merus about six times as long as wide at base; carpus about half-length of merus, distal ventral margin without spine; propodus near as long as carpus, ventral margin bearing 6 spines and distal one pair of spines; dactylus slightly longer than half-length of propodus, slightly curved, bearing short setae near tip. Fourth pereiopod ( Fig. 4 J, K) similar to third pereiopod. Fifth pereiopod ( Fig. 4 L, M) slender than third and fourth pereiopod; propodus distinctly longer than carpus, with ventral margin bearing transverse rows of setae and two small spines; dactylus about half-length of propodus.

Pleon ( Fig. 4 A) with first to fifth pleura rounded postero-ventrally. Telson ( Fig. 5 D) much shorter than uropods, 1.4 times as long as wide at base, dorso-lateral margin bearing two pair of moderately large spines, anterior and posterior pair situated about 1/2 and 3/4 length of telson, respectively; posterior margin only slightly convex, bearing two pairs of spines, with mesial about four times as long as lateral.

Second pleopod ( Fig. 5 B) without appendix masculine both sexes. Uropod ( Fig. 5 D) with endopod slightly distinctly longer than exopod; exopod with postero-lateral corner acute, strongly produced, accompanied with one spine slightly shorter than posterior margin of exopod.

Etymology. “spinos” meaning spines, the ventral margin of the third and fifth pereiopod are bearing row of spines.

Distribution. Present only known from Sanya Gulf and Beibu Gulf, the South China Sea.

Remarks. Automate spinosa sp. nov. is assigned to the A. evermanni species group on account of having the following characters: the absence of the rostrum; the stylocerite not reaching the distal end of basal segment of the antennular peduncle; the scaphocerite not reaching the distal end of the second segment of antennular peduncle ( Anker & Komai 2004). The present new species is most similar to A. rectifrons for the nearly straight frontal region of the carapace, the rostrum absent. Morphologically, A. spinosa sp. nov. is specifically differing from A. rectifrons in the disto-lateral tooth of the scaphocerite distinctly beyond the distal segment of palp of the mandible well developed rather than narrow ( Chace 1972, Fig. 24G); the ischium of the major cheliped unarmed with spines on superior distal margin; the propodus of the third and fourth pereiopod bearing 6 spines ventrally rather than only robust setae ( Chace 1972, Fig. 24O, P); the dactylus of posterior three pereiopod long than half-length of the propodus rather than shorter than half-length of the propodus ( Chace 1972, Fig. 24O, P), and in the dorsal spines of the telson not very small as shown by Chace (1792, Fig. 24C). Geographically, A. rectifrons occurs from the Atlantic Ocean ( Chace 1972; Anker & Komai 2004), while the present new species is collected from the Western Pacific.

Figures

FIGURE 4. Automate spinosa sp. nov., holotype, female (MBM 159184), CL 4.9 mm. A, body in lateral view; B, anterior part of carapace, dorsal view; C, same, lateral view; D, E, major cheliped, lateral view; F, G, same, fingers, lateral view; H, right third pereiopod; I, same, propodus and dactylus; J, right fourth pereiopod; K, same, propodus and dactylus; L, right fifth pereiopod; M, same, propodus and dactylus; N, hook-shaped epipod of third maxilliped to fourth pereiopod. Scale bars: a = 2 mm; c, d = 1 mm; b, e – m = 0.5 mm.

FIGURE 5. Automate spinosa sp. nov., holotype, female (MBM 159184), CL 4.9 mm. A, right first pleopod; B, right second pleopod; C, sixth abdominal segment, lateral view; D, telson and right uropod; E, right mandible; F, right maxillule; G, right maxilla; H, right first maxilliped; I, right second maxilliped; J, right third maxilliped. paratype, female (MBM 270172), CL 3.1 mm. K, anterior margin of carapace; L, minor cheliped; M, left second pereiopod. Scale bar = 0.5 mm.