Amphibetaeus jousseaumei Coutière, 1896

Marin, Ivan, Sheibani, Raheleh & Sari, Alireza, 2014, A re-description of rare alpheid shrimp Amphibetaeus jousseaumei (Coutière, 1896) and description of a new species of the genus Athanopsis Coutière, 1897 (Crustacea: Decapoda: Alpheidae) from Iranian coast of the Persian Gulf, Zootaxa 3846 (3), pp. 398-410 : 399-403

Amphibetaeus jousseaumei Coutière, 1896

( Figs. 1–3 )

Betaeus jousseaumei Coutière, 1896a: 313 , figs. 1–12; Coutière, 1896b: 236. Amphibetaeus jousseaumei Coutière, 1896c: 384 .

Material examined. — Neotype, male (cl. 11.2 mm, tl. 30.0 mm) (SMF-43232) and female (cl. 12.0 mm, tl. 33.0 mm, female material get lost after drawing)—Northwest Indian Ocean, Qeshm Island, the Persian Gulf, Iran, 26º51′N, 56º08′E, subtidal, under stone, 10Jan2008.

Description.—Rather large shrimp with robust body. Carapace glabrous, smooth, with well marked cardiac notch ( Fig.1 a), no any teeth, orbital hood completely overlapping eyes ( Fig. 1 b, c); dorsal or lateral carina absent; pterygostomial angle rounded, slightly produced. Eyes large, with well pigmented cornea, eyestalk robust, distally bluntly produced ( Fig. 1 b).

Antennular peduncle ( Fig. 1 c) robust; basal segment with large, strong tooth ventromedially, stylocerite robust, triangular, slightly overreaching basal antennular segment; second segment subequal, about as long as wide; distal segment as long as wide; upper flagellum short, biramous, with 5 proximal robust segments, shorter ramus with 3–4 segments and each with group of 2–3 aesthetascs, longer ramus with more than 10 segments. Lower flagellum longer than upper and well developed.

Antenna ( Fig. 1 a, h) with robust basicerite with acute robust ventral tooth; carpocerite slightly overreaching to just beyond the tip of scaphocerite, about twice longer than wide; scaphocerite well developed, subequal to length of antennular peduncle, lamina about 1.3 times longer than wide, blade slightly overreaching distolateral tooth, lateral border slightly convex, distolateral tooth small and blunt.

Abdominal somites smooth, ventrolateral posterior border of fourth and fifth somites pubescent, sixth somite with fused triangular plate at posterolateral edge ( Fig. 1 e). Telson ( Fig. 1 d, e) about 1.5 times longer than proximal width, tapering distally, lateral margins slightly convex, dorsal surface with 2 pairs of developed submarginal dorsal spines, about 0.2 of telson length, subequal in slight depressions; distal margin of telson ( Fig. 1 f) rounded, with submarginal row of short setae and longer terminal posterior setae, distolateral corner with 2 pairs of spines, lateral spines about half length of mesial spines, between posterior spines and longer terminal posterior setae. Uropods overreaching telson ( Fig. 1 d); exopod of uropod ( Fig. 1 g) with feebly convex lateral margin covered with small setae, dieresis with subdistal movable acute spine, distolateral corner subzngulated, unarmed, midpart bearing deep rounded depression.

Mandible ( Fig. 2 a) robust, with strong molar process, incisor process with 5 teeth and palp 2–segmented, reaching about to end of incisor process. Maxillula ( Fig. 2 b) with bilobed palp, upper lobe having 2 slender setae distally and lower lobe with single longer and thicker setae distally; upper lacinia stout, with numerous setae on mesial margin, lower lacinia slender with 5–10 long spines and numerous small setae distally. Maxilla ( Fig. 2 c) with well developed tapering palp, distal endite feebly bilobed with small setae on mesial margin, proximal endite short, thumb-like, with scaphognathite broad. First maxilliped ( Fig. 2 d) with well developed 2-segmented palp; epipod large and broad, bilobed; exopod very long, slender, with small caridean lobe fringed with plumose setae; distal endite broad with numerous setae medially, separated by notch from broadly rounded and less setose proximal endite. Second maxilliped ( Fig. 2 e) normal, with large ear-shaped epipod; exopod large and slender, with several long setae distally; coxa rounded with few setae mesially; ischiobasis robust, propodus stout, greatly convex distodorsally; dactylus about 2.5 times longer than wide, with numerous simple spines along outer margin. Third maxilliped ( Fig. 2 f) exceeding antennular peduncle by tip of ultimate segment; with ear-shaped epipod, arthrobranch and setobranch; exopod slender, equal to the length of antepenultimate segment, antepenultimate segment about 5 times longer than broadest width; penultimate segment about 0.4 times as long as antepenultimate segment, about twice longer than wide; distal segment slender, about 2 times longer than penultimate and about 5 times longer than wide, tapering distally, with more than 15 rows of stout setae and spines distally.

First pereiopods unequal in size and shape, both in male and female, carried flexed. Total length of major chela equal to postorbital length of carapace ( Fig. 3 a). Major cheliped ( Fig. 3 a–d) with slender proximal segments and stout chela; ischium about 1.5 times as long as wide, unarmed; merus slender, ventrally depressed, about 4 times longer than wide, widening distally, with straight smooth margins; carpus stout, cup-shaped, unarmed. Palm ( Fig. 3 b-d) stout, smooth, subcylindrical about 2 times as long as proximal width, subequal to fingers in length; dorsal side depressed proximally; lateral margin near dactyl-propodal articulation transversely constricted, adhesive p;aque large. Fingers ( Fig. 3 b–d, e, f) strong, compressed surfaces smooth, tips strongly curved, crossing, fixed finger with pointed tip, cutting edgewith 2 proximal triangular teeth and small tvercle-like tooth in distal third, midpart with large deep fossa; movable finger slightly shorter than fixed finger, cutting edge with 2 triangular proximal teeth and large flattened tooth fitting into fossa on the fixed finger. Minor cheliped ( Fig. 3 g) significantly smaller than major; ischium small, about 1.5 times as long as wide; merus slender, about 7 times as long as wide, ventral margin depressed, unarmed; carpus ( Fig. 3 h) stout, cup-shaped; palm stout, swollen, surfaces smooth, slightly shorter than fingers; fingers slender, compressed, tips sharply pointed, crossing, cutting edges forming thin plate with small triangular teeth on both cutting edges at distal third.

Second pereiopod ( Fig. 1 i) slender; coxa with setobranch and hook-like epipod; basis slightly longer than wide, unarmed; ischium and merus subequal, about 8 times longer than wide, unarmed; carpus longer than merus, subdivided into 5 segments, with ratio about 5:1:1:1:2, with distal segment subequal to length of chela; chela small, palm subequal to the length of fingers, about 1.7 times longer than wide, fingers simple, about twice as long as wide, tips sharply pointed.

Ambulatory pereiopods robust, with slender simple dactylus. Third pereiopod ( Fig. 1 j) with robust basal segments; coxa with setobranch and hook-like epipod; ischium as long as wide, unarmed; merus with convex smooth margins, about 3.5 times as long as maximum width, unarmed; carpus relatively slender, subequal to propodus, about 4 times as long as maximal width, expanded distally, with small distal spine on flexor margin; propodus about 4 times longer than wide; flexor margin with 2 spines and one pair of small distal spines; dactylus simple, sharply pointed, slightly curved, about 0.3 times length of propodus and 3 times longer than proximal width. Fourth and fifth pereiopods similar to third.

Second pleopod with appendix masculina ( Fig. 1 k) twice shorter than appendix interna, 0.15 times length of endopod.

Remarks. —Originally, the species was well described by Coutière (1896 a, b) and our specimens are identical to its original description. Unfortunately, the bodies and most appendages of the all syntypes designated by Coutière and deposited in the collection of MNHN were lost and only one large chela is still deposited. This chela indicated as a lectotype was re-described by Anker & Jeng (2006) with presented diagnosis of the genus. At the same time, new record of this rare species which has been never found since its original description in 1896 as well as the absence of the type specimen are the reasons for presenting this re-description from the Persian Gulf and designation of neotype.

Coloration. —Not recorded. The species is probably translucent with some reddish tiny chromatophores.

Habitats. —The described specimens were found on sand-muddy flat bottom, under large boulder, together with large burrowing ghost shrimp Neocallichirus jousseaumei (Nobili, 1904) (Callianasidae) and two echiuran individuals. It was already mentioned that the species could be symbiotic with burrowing ghost-shrimps, sipunculans or echiurans ( Coutière 1899). Association with large burrowing callianassid shrimps is characteristic for some alpheids (for example, Anker & Marin, 2009).

Distribution. —Known only from the northwest part of the Indian Ocean: from Qeshm Island, Iran; Bab al Mandab Strait between the Red Sea and the Gulf of Aden; from Tadjourah (the Republic of Djibouti) and Perim (off southwestern coast of the Republic of Yemen).

Figures

FIGURE 1. Amphibetaeus jousseaumei Coutière, 1896, a-j female, k male (SMF- 43232): a — carapace, lateral view; b— front of carapace, lateral view; c — same, dorsal view; d — last abdominal segments, telson and uropods, dorsal view; e — same, lateral view; f — distal margin of telson, dorsal view; g— exopod of uropods, dorsal view; h — antenna; i — second pereiopod; j— third pereiopod; k — endopod of second pleopod.

FIGURE 2. Amphibetaeus jousseaumei Coutière, 1896, female: a — mandible; b — maxillula; c — maxilla; d — first maxilliped; e — second maxilliped; f — third maxilliped.

FIGURE 3. Amphibetaeus jousseaumei Coutière, 1896, a-g female, h male (SMF- 43232): a — carapace and appendages; b – c — first major pereiopod, different views; e, f— same, fingers; g — minor first pereiopod; h— same, chela.