Alpheus sulcipalma Purushothaman & Bharathi & Damodhar & Ajith Kumar & Lal 2023, sp. nov.
Creators: name: Purushothaman, P.
name: Bharathi, S.
name: Damodhar, A. T.
name: Ajith Kumar, T. T.
name: Lal, K. K.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Alpheidae
Alpheus
Alpheus sulcipalma

description: Alpheus sulcipalma sp. nov.
(Fig. 1–4)
Material examined
Holotype: male, CL 9.0 mm, Accession No.: NBFGR/ALPASUL–00, ID No. NBFGR: DBTLD220, Rocky dead coral, Agatti Island, Lakshadweep, India (10° 50ʹ 38.6" N, 072° 11ʹ 22.1" E), 0.5–1.0 m, hand net, December 2018. Paratypes: 1 male, CL 7.0 mm, Accession No: NBFGR/ALPASUL–01, ID No. NBFGR: DBTLD:42; 1 female, CL 4.5 mm, Accession No: NBFGR/ALPASUL–02, ID No. NBFGR: DBTLD:138, rocky dead coral, Agatti Island, Lakshadweep, India, 0.5–1.0 m, hand net, January 2019. 7 males, 10 females (CL 4.5–9.0 mm; Table 2) deposited in the Peninsular and Marine Fish Genetic Resources (PMFGR) centre, ICAR–NBFGR, India.
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IN—India; FB—French Polynesia; US—United States
Description
Small-sized species (CL 3.5–9.0 mm). Carapace (Figs. 1A, B) glabrous, smooth, not setose or tubercle. Rostrum slender, acute, straight directed forward, overreaching mid-length of first article of antennular peduncle, lateral margin bearing few small setae on each side, without rostral carina. Orbital hood moderately swollen, slightly higher than rostrum; anterior margin unarmed; margin between rostrum and orbital hood slightly concave. Pterygostomial angle broadly rounded. Cardiac notch well developed and V-shaped.
Pleon smooth, subcylindrical, and slightly compressed laterally; pleura of pleomeres 1–4 marginally rounded, pleuron of pleomere 2 subtriangular, pleuron of pleomere 5 with leaf-like process in posteroventrally (Fig. 3H). Telson (Fig. 1C) glabrous, trapezoidal, tapering posteriorly, about 2.6–3.1 times as long as posterior width and 2.0- 2.2 times as long as proximal width, dorsal surface smooth with 2 pairs of movable spines, proximal and second pairs located at 0.4 and 0.65 of telson length, respectively; posterior margin convex, fringed with numerous long plumose setae, posterolateral angle with 2 pairs of movable spines, mesial spine slender and about 2.0 times as long as a lateral one.
Eyes (Figs. 1A, B) small, fully covered with orbital hood in both dorsal and lateral view; cornea dark in colour with globular shaped; anteromesial margin moderately produced and rounded in anteriorly.
Antennular peduncle (Fig. 1B) moderately slender, almost reaching distal margin of antennal scaphocerite; stylocerite flatted, terminating an acute spine, overreaching distal margin of first article of peduncle; first article short, with broad ventromesial carina; second article long, about 2.1–2.4 times as long as maximum width and 1.6–1.7 times of first article; third article slightly longer than first article; antennular flagella asymmetrical in length; outer flagellum longest, slender, gradually tapering towards terminal units; outer flagellum short and thicker than inner flagellum with numerous aesthetascs on about 10–12 segments.
Antenna (Fig. 1A, B) with basicerite rather moderate, ventrolateral margin armed with a slender spine; scaphocerite subovate, thin, tapering distally, about 3.1–3.2 times as long as maximum width, lateral margin straight and barely concave proximally, distolateral tooth well- developed, sharp, overreaching well beyond distal margin of lamella and third article of antennular peduncle; carpocerite long, thick, overreaching distal margin of scaphocerite; flagellum thick, tapering towards to terminal end and longer than antennular flagella.
Mouthparts not dissected and typical for this genus in external observation. Third maxilliped (Fig. 1E) slender, slightly overreaching distal margin of antennal scaphocerite; antepenultimate article broad, longest, about 4.1–4.4 times as long as maximum width, dorsolateral margin with thick longitudinal ridge with numerous long setae, ventral surface with a sharp carina mesial to distal margin with numerous small setae; penultimate article short, about 0.42 times of antepenultimate and 2.3 times of maximum width, slightly widen distally, numerous long setae on dorsal and lateral surface; ultimate article about 4.6 times as long as maximum width and 1.8 times of penultimate article, tapering gradually towards terminal end, lateral and dorsal surface furnished with numerous rows of long serrulate setae, distal margin with stout long setae; exopod long, overreaching distal margin of antepenultimate article with numerous small setae on distally. Arthrobranch large with a faint terminal tooth with few setae on laterally (Figs. 1E, F).
Male major cheliped (first pereiopod: Figs. 2A–D) broad, larger, laterally compressed, extending beyond distal margin of antennal scaphocerite by half length of palm and dactylus; ischium very short and stout; merus stout, broad, about 1.9 times as long as broad, distodorsal margin rounded and extended somewhat angled; mesial margin smooth, with few simple small and long setae, distomesial angle blunt, without tooth; carpus very short, cup-shaped, distodorsal margin with few long setae; chela broad, stout, slightly compressed, about 2.3 times as long as broad, 1.5 times of CL, surface almost smooth with numerous minute hairy form setae, minute granulated with numerous setae on distal half of palm and fingers; dorsal shoulder rounded, strongly overhanging, latter deep notch, moderately broad; dorsolateral surface of palm with deep shallow triangular groove extending from posterior of dorsal notch, mixing with linea impressa and continued posteroventral of lateral surface; dorsomesial surface with longitudinal groove extending from dorsal notch to near linea impressa anteriorly; ventral shoulder blunt, rounded, protruding forward, with deep ventral notch, somewhat 'V' shaped; ventromesial and ventrolateral surface with broad and deep groove on each side; fingers about 0.63 times as long as palm; pollex stout, terminating acute tip and curved, distolateral margin of socket for plunger sinuous with a small tooth like process, distomesial margin with sinuous; dactylus slightly longer than pollex, distal margin broadly rounded, acute tip, with few stout setae; plunger stout, broad, smooth, anteriorly rounded and thick in distally; adhesive discs well found on dactylus and palm.
Female major cheliped (first pereiopod Figs. 2E, F) broad, extending beyond the distal antennal scaphocerite by three fourth of chela; ischium, merus and carpus similar with male; chela broad, stout, slightly swollen, about 2.4 times as long as broad, 1.1 times of CL, surface with numerous minute and long hairy form setae; dorsal shoulder rounded, strongly overhanging with deep broad notch; dorsolateral surface of palm with deep shallow and narrow triangular groove extending from posterior of dorsal notch, mixing with linea impressa and continued posteroventral of lateral surface; dorsomesial surface with narrow triangular groove extending from dorsal notch to near linea impressa; ventral shoulder blunt, rounded, protruding forward, with deep ventral notch, more or less 'U' shaped; ventromesial and ventrolateral surface with broad and deep groove on each side; fingers compressed, about 0.51 times as long as palm; pollex stout, terminating acute tip and curved, distomesial margin with sinuous; dactylus slightly longer than pollex, distal margin very broadly rounded, with few small setae; plunger stout, smooth, rounded anteriorly and thick in distally; adhesive discs well found on both dactylus and palm.
Minor cheliped (Figs. 2G, H) slender, simple, and non-balaeniceps in males and females. Minor cheliped of male very smaller than major cheliped; ischium very short; merus stout, about 2.1–2.9 times as long as broad, distodorsal margin somewhat angle sharped in lateral view; mesial margin with few simple small and long setae, distomesial angle blunt and rounded; carpus short, cup-shaped; chela moderately stout, about 3.8 times as long as broad, surface smooth with few setae, especially dorsolateral surface with very setose; palm about 1.6 times as long as height with a prominent form of linea impressa proximally, distodorsal margin slightly depressed; fingers equal in length, about 1.3 times as long as palm, without any ridges or grooves, with a strong hook-like tooth and crossing distally, covered with small and long setae; dactylus slightly slender than pollex, a proximal site with two small crests, cutting edges simple, thin, blade-like with small setae throughout the edges; adhesive discs small on dactylus and palm. Female minor cheliped similar with the male.
Second pereiopod (Fig. 3A) slender, simple, overreaching distal margin of scaphocerite by the length of carpus and chela; ischium long, about 6.0 times as long as broad; merus equal length to ischium without any spine; carpus subdivided into five segments, proximal segment longest and about 5.5 times as long as width, fifth segment twice the length of fourth; a ratio of carpal segments 4.0: 2.7: 1.0: 1.0: 2.0; chela simple, about 1.8 times as long as a terminal segment of carpus; fingers slightly longer than palm furnished with several groups of simple setae.
Third pereiopod (Figs. 3B, C) moderately slender, overreaching distal margin of scaphocerite by length of dactylus; ischium with a movable spine; merus broad, about 4.0 times as long as maximum width with minute several setae on dorsally, distomesial margin unarmed; carpus about 4.1 times as long as width, 0.6 times of merus, and slender than merus; propodus about 6.0 times of maximum width, 0.7 times of merus, ventral margin with a row of 7–8 spiniform setae and a pair of spiniform setae in distoventral margin; dactylus simple, conical, long, curved, with acute terminal end, about 0.4 times as long as propodus. Fourth pereiopod (Figs. 3D, E) similar to third one, slightly slender, overreaching scaphocerite by length of dactylus; ischium with a movable spine; propodus about 6.1 times as long as width, ventral margin armed with 7–8 stout spiniform setae and a pair in distoventral margin with several simple and long setae; dactylus similar with third pereiopod. Fifth pereiopod (Figs. 3F, G) more slender than third and fourth, reaching mid-length of scaphocerite; ischium without ventrolateral spine; merus about 6.7 times as long as maximum width, 0.75 times of carpus; carpus slender than merus about 6.3 times of width; propodus about 7.3 times as long as width, with numerous long setae in dorsal and ventral surface, a row of 6–7 spiniform setae in ventral margin with a pair in distally, and distoventral half covered with 8–10 transverse rows of serrulate setae found as cleaning brush; dactylus about 0.38 times of propodus and similar with third pereiopod.
Male first pleopod (Fig. 1G) with a reduced form of endopod, much smaller than exopod, bearing few stiff setae along the distal margin, about 0.2 lengths of exopod. Male second pleopod with similar length of exopod and endopod, along the distal margin covered with long setae; appendix masculina small and thin about 0.82 times as long as appendix interna, lateral and distal margin covered with long stiff setae (Fig. 1H). Female first pleopod (Fig. 1I) endopod reduced, spatulate shaped, with few distal setae; second pleopod similar to those of male; protopod broad, thick with several long setae on inner margin (Fig. 1J).
Uropod (Fig. 1D) broadly rounded and slightly overreaching distal margin of telson; protopod with inner and outer lobes each produced into a triangular acute tooth, distolateral margin with few long tuft setae; exopod broad and almost equal length to endopod, bearing a small distolateral tooth and a stout spiniform distolateral seta; diaeresis barely trilobed, distal margin fringed with long plumose setae; endopod fringed with long setae from inner to distal margins.
Colour pattern
The live colour pattern (Fig. 4A) of the new species shows exhibits sexual dimorphism. Generally, males with carapace, antennal segments, abdomens, pereiopods, pleopods, uropod, and telson translucent light greenish; major pereiopod fingers with light violet in distally. In dead condition, body with a translucent light brown (Fig. 4B). Female body and appendages are generally translucent light violet; distal of half of the fingers in major pereiopod with light violet.
Habitat
All the specimen were found in the crevices of dead and live coral rocks in the intertidal zone of Agatti Island at 0.5 to 1.0 m depths (see Table 2).
M—Male; F B—Female Berried; F—Female
Distribution
Presently known only from waters of Agatti Island of Lakshadweep, India.
Parasite
Some of the individuals of A. sulcipalma sp. nov. were found infested with bopyrid parasite, Argeiopsis inhacae Kensley, 1974, in branchial region of cephalothorax. Carapace shows a bulbous structure which can be seen in lateral view (fig 4B–D). Most of the boyprid parasites were adult females carrying numerous matured eggs.
Etymology
The species name is derived from Latin, Sulcus (= groove or depression) and palma (palm), which refer to the strong triangular structure of groove on the dorsolateral surface of palm in major cheliped of both the sexes.
description: Published as part of Purushothaman, P., Bharathi, S., Damodhar, A. T., Ajith Kumar, T. T. & Lal, K. K., 2023, Morphological and molecular approaches revealed a new species of snapping shrimp genus Alpheus Fabricius, 1798 (Decapoda: Caridea: Alpheidae) from Lakshadweep Islands, India, pp. 426-442 in Zootaxa 5227 (4) on pages 428-434, DOI: 10.11646/zootaxa.5227.4.2, http://zenodo.org/record/7518860