Andamancalliax poorei Sepahvand & Tudge 2022, sp. nov.
Creators: name: Sepahvand, Vahid
name: Tudge, Christopher
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Eucalliacidae
Andamancalliax
Andamancalliax poorei

description: Andamancalliax poorei sp. nov.
(Figs. 1–3)
Type material. Holotype: female (tl 23.6 mm, cl 6.7 mm), Gulf of Oman, 25.5747848ºN, 53.7012269ºE, 200 m, INIOC-2-14.
Diagnosis: distinct dorsal oval on carapace; prominent sharp rostrum; maxilliped 3 with long exopod, truncate setose dactylus and crista dentata with5 large, prominent spines; unequal dissimilar chelipeds, minor one with elongate fingers; presence of a dorsal plate on the uropodal exopod.
Description: Rostrum sharply triangular in dorsal view, shorter than eyestalks. Carapace as long as pleomeres 1 and 2 combined, flat, with dorsal oval (Fig. 1A–B). Eyestalks (Fig. 1C) oval, 1.5 times as long as wide, overreaching distal margin of antennular basal article; dorsal surface convex; cornea pigmented, located in distal part. Antennular peduncle (Fig. 1B, E) shorter than antennal peduncle, ultimate article 2 times as long as penultimate article, penultimate article shorter than basal article. Antennal peduncle (Fig. 1B, D) with article 3 slightly longer than article 2, article 4 longest, about 2 times as long as article 5. Maxilliped 3 (Fig. 2A–C) with long, thin exopod; basis with 7 mesial spiniform setae along lower margin; ischium subquadrate, 1.2 times as long as wide, tapering to two-thirds of its greatest proximal width, with 5 mesial teeth (= crista dentata) along upper margin; merus rectangular, slightly longer than ischium, flexor margin convex; carpus triangular, shorter than merus; propodus subquadrate, 1.3 times wider than long, and rounded on flexor margin; dactylus broadened distally, about 1.1 times as long as propodus, distal margin oblique, densely setose.
Pereopods 1 chelate, asymmetrical. In major cheliped (Fig. 2D–E) ischium lower margin armed, bearing small, rounded teeth. Merus slightly broader and longer than ischium, unarmed. Carpus 0.8 times as long as merus, 1.5 times as broad as long, mesial surface with broadly uncalcified proximal part ventrally below articulation with merus; distal margin with prominent tooth creating a notch between articulation and angle of lower margin. Chela about three times as long as carpus. Palm about as long as broad. Fixed finger thick, cutting edge with proximal tubercle and triangular tooth, smooth. Dactylus slightly shorter than palm, thick, twice as long as broad, with row of setal tufts along dorsal margin (Fig. 2E); cutting edge as a longitudinal carina, sigmoid in proximal half, and straight in distal half. Dactylus tip damaged and therefore slightly truncated.
Minor cheliped (Fig. 2F) with ischium two times as long as broad, lower margin with a tooth distally. Merus shorter than ischium, 1.4 times as long as broad, convex on dorsal margin; mesial surface with uncalcified groove. Carpus 0.6 times as long as merus, and 0.7 times as long as broad, mesial surface with uncalcified part as in larger cheliped. Propodus 5 times as long as carpus; fixed finger simple, lateral surface with row of setae along cutting edge, cutting edge smooth. Dactylus slender, 1.6 times as long as palm; smooth and straight.
Pereopod 2 (Fig. 3A) unarmed. Merus longest, with numerous setae in proximal two-thirds of sinuous lower margin. Carpus triangular, broadest distally. Chela as long as carpus; lower portion of propodus with setal patches; prehensile margins of both fingers acute, straight edge over most of length; upper margin of dactylus almost sigmoid.
Pereopod 3 (Fig. 3B), ischium short, merus twice as long as wide, lower margin slightly convex in middle part. Carpus triangular in lateral view, slightly shorter than merus, lower part setose along roundly convex ventral margin. Propodus with roundly protruded proximal angle, lateral surface with a row of setae along lower margin. Dactylus heart-shaped, two-thirds as long as propodus.
Pereopod 4 (Fig. 3C–D) merus 3 times as long as wide; carpus 3 times as long as wide; propodus setose, with 2 long, dorsal, distal setae overlapping dactylus.
Pereopod 5 (Fig. E) all articles unarmed. Merus longest. Propodus about 0.7 length of carpus, convex on dorsodistal margin, dactylus 0.3 times as long as propodus and curved.
Pleonites (Fig. 1A, F) smooth, dorsally glabrous; pleurae 3–5 each with tuft of setae disto-laterally; pleonite 6 as long as wide. Pleopod 1 (Fig. 3F) uniramous, two-articled; pleopod 2 (Fig. 3G) biramous, narrowly foliaceous, endopod with slender appendix interna.
Telson (Fig. 1G) semicircular in dorsal view, wider than long; lateral margins convergent distally in proximal half; posterior margin almost convex, without median tooth. Uropodal endopod (Fig. 1G) ovoid, proximal margin more convex than distal margin, widest at midpoint, as long as wide, longer than telson, without facial setae; exopod (Fig. 1H) broadly subovate, approximately as long as wide, dorsal plate well developed, fringed distolaterally by dense setae; posterolateral part of exopod with numerous spiniform setae.
Etymology: The new species is named in honor of Dr. Gary C. B. Poore for his extensive contributions to mud shrimp and ghost shrimp taxonomy and phylogeny.
Remarks: The present new species has a truncate setose dactylus on maxilliped 3 and the presence of a dorsal plate on the uropodal exopod; both are traits common to the family Eucalliacidae. The new species also agrees with the generic diagnosis of Andamancalliax Sakai, 2011, particularly in the prominent sharp rostrum and the unequal dissimilar chelipeds, with the minor one having elongate fingers (Poore et al., 2019; Poore, 2021). Sakai (2002) failed to describe or illustrate the crista dentata of maxilliped 3 in Andamancalliax andamanica (as Calliax andamanica). The few (4–5), large, prominent spines described here and in A. arafura are commonly reported in eucalliacid species (Poore, 2021).
The new species differs from the type description of A. andamanica in that the ischium of the major cheliped is armed (vs unarmed), the presence of an obvious carina on the cutting edge of the major cheliped dactylus (vs no carina), distal margin of carpus of large cheliped with a tooth creating a notch between the articulation and the angle of the lower margin (vs no tooth or notch) and a more oval uropodal endopod (vs rectangular in shape). Andamancalliax poorei sp. nov. differs from A. arafura in that even though the ischium of the minor cheliped is armed on the ventral margin with a subdistal process in both species, it is blunt and tooth-like (vs sharp and spine-like), the propodus and dactylus of the minor cheliped is unarmed (vs armed), and the dorsal plate on the uropodal exopod is more distinct. Additionally, the basis of maxilliped 3 in A. poorei possesses 7 spiniform setae (vs 4 teeth in A. arafura). This feature was not mentioned for A. andamanica by Sakai (2002).
It is worth mentioning that Sakai (2011) defined the genus Andamancalliax without a carapace dorsal oval, after stating it was “indistinct” in the diagnosis of Andamancalliax andamanica (as Calliax andamanica) in Sakai (2002), but our new species and A. arafura clearly bear this character. Additionally, two of the three species of Andamancalliax, including A. arafura Poore, 2021 and A. poorei sp. nov., have the maxilliped 3 bearing an exopod (short in A. arafura and long in A. poorei sp. nov.), while Sakai reported that the maxilliped 3 in A. andamanica (Sakai, 2002) is without an exopod.
description: Published as part of Sepahvand, Vahid & Tudge, Christopher, 2022, A new species of the ghost shrimp genus Andamancalliax Sakai, 2011 from Iran (Crustacea: Decapoda: Axiidea: Eucalliacidae), pp. 86-92 in Zootaxa 5213 (1) on pages 87-91, DOI: 10.11646/zootaxa.5213.1.6, http://zenodo.org/record/7350177