Munidopsis parvatee Periasamy & Kurian & Ingole 2023, sp. nov.
Creators: name: Periasamy, Rengaiyan
name: Kurian, Palayil John
name: Ingole, Baban
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Galatheidae
Munidopsis
Munidopsis parvatee

description: Munidopsis parvatee sp. nov.
Fig 2–4
Material examined: female holotype: NCPOR /HYD–CIR/0048, ♀ (CL 14.2 mm, PCL 10.4 mm) Central Indian Ridge, Indian Ocean, R / V ‘ MGS Sagar’ cruise MGS35 (Station no: MGS35B– BD25), 27 April 2020, 24° 42′ 47.88′′ S, 70° 1′ 54.12′′ E, 1981 to 2033 m, Benthic Sledge, Coll. Periasamy R, samples in 90% ethanol.
Paratypes: One specimen NCPOR /HYD–CIR/0049 from the same locality as the holotype.
Ecological note: The specimen was collected along with three types of deep-sea corals, two types of brittle stars, shrimps, dead Gastropod shells, and Isopods from a basalt rocky bottom.
Coloration: The yellow-orange base colour of the body.
Distribution: Seamount is located near the Edmond vent field, Central Indian Ridge (CIR), in a depth range of 1981–2033 meters.
Etymology: The species name “ parvatee ” is a Hindi word given based on its habitat i.e., seamount. parvatee means belong to the mountain.
Description: The carapace (without rostrum) is approximately 1.34 times as long as broad. Frontal margins are tilted. Lateral margins are feebly convex, each with three to six prominent spines; small anterolateral spine; one or two spines on the anterior branchial margin; one to three spines on the posterior branchial margin (spine on the lateral base of posterior cervical groove strongest; posterior one or two spines usually reduced); scale-like tubercles and short ridges present among spines; especially on posterior branchial margin. Posterior margin ridged, and tubercles laterally. Dorsal surface with regions clearly defined; covered with numerous tubercles; tubercles fairly scale-like on posterior branchial region; conical on anterior branchial; cardiac and gastric regions. Six pairs of strong spines are present along the dorsal midline: three pairs of spines in the gastric region; two pairs of spines in the cardiac region (each in the anterior and posterior cardiac region); and one pair of very small spines on the intestinal region (Figure 2A). The gastric region is somewhat eminent. The cervical groove is different (Figures 2 & 3).
Rostrum distinctly elongate; flat; and dagger-shaped; 0.5 times as long as the remaining carapace length; 4 times longer than broad; narrow; horizontal; dorsal surface covered with rugae (fine serrations); weakly depressed proximally (Figures 3A).
Eyestalk movable. Cornea oval; globular; cupped in the anterolateral end of the ocular peduncle. Ocular peduncle without eye spine; reaching proximal 0.2 of the rostrum (Figures 3A). The pterygostomial flaps with broad tubercles on the lateral surface; anterior end blunt (Figure 3B).
Abdominal tergites unarmed; tergites 2 and 3 each with two transverse ridges medially connected and laterally separated by deep grooves; lateral part of dorsal surfaces smooth (Figures 3H).
Sternal plastron longer than broad (Figure 3D). Sternite 3 is 1.5 times broader than long; divided into two parts by a median groove; anterior margin serrated; with acute anterolateral spines. Sternite 4 three times broader than long; anterolateral surface depressed and sloping anteriorly. Sternites 5–7 medially grooved; separated from one another with elevated; transverse ridges (Figure 3D).
Antennal peduncle stout; reaching at least proximal half of rostrum. Article 1 immovable; with a short distomesial spine. Article 2; article 3; and article 4 unarmed (Figure 3A).
Antennular peduncle with basal article longer than broad; distal margin armed with strong ventrolateral and dorsolateral (rarely with affiliated spine) spines; lateral face inflated; ventral surface with short rugae (Figure 3C).
Third maxilliped stout; ischium slightly longer than broad; approximately 0.5 times merus length; distoflexor corner acute; crista dentata well developed. Merus longer than broad; extensor margin rugose; flexor margin with small median spines and strong proximal process (divided into two spines); ventral surface with rugae. Carpus short; unarmed. Propodus with distoflexor margin convex (Figure 3F&G).
Telson is composed of eight separate plates; covered with scale-like tubercles (Figure 3G).
P1 subequal; distinctly elongate; 5 times PCL; each segment covered with numerous scale-like tubercles longitudinally arranged on surfaces and margins and bearing fine setae. Ischium with strong dorsodistal spine; ventrodistal margin anteriorly produced. Merus approximately 1.8 times PCL; distal margin with strong dorsal; mesial; ventral; and lateral spines; dorsodistal spine followed by a row of spines; distomesial spine strongest; followed by two or three slender spines; ventrodistal spine followed by two or three spines (usually on proximal half) along the midline of the ventral surface. Carpus approximately 0.6 times merus length; distal margin with strong dorsal; mesial and lateral spines; dorsodistal spine followed by spines and pointed tubercles; distomesial spine occasionally followed by few spines. Palm is relatively compressed; approximately 0.6 times merus length; 5 times as long as broad; mesial margin with a row of small spines or pointed tubercles. Fingers 0.5 times palm length; slightly spooned distally; occlusal margins straight and denticulate; bearing fringe of simple setae; with several triangular teeth on a movable finger (Figure 4A–D).
P2 –4 slender, sparsely setose; P2 approximately 2.2 times PCL; falling short of distal margin of P1 merus; lateral surfaces of Ischia; meri; carpi; propodi covered with scale-like tubercles. Meri compressed; subequal in breadth but decreasing in length posteriorly; P2 merus approximately 0.8 times of PCL and 5 times as long as broad; P3 merus 1-time P2 merus length; P4 merus 0.7 times P2 merus length; extensor margin tuberculate; armed with a strong distal spine; flexor margin tuberculate; without a distinct spine. Carpi subequal in length; approximately 0.5 times P2 merus length; extensor surface with two longitudinal ridges each covered with scale-like tubercles and armed with a distinct distal spine; spine on mesial ridge much more prominent; flexor margin unarmed. Propodi subcylindrical; subequal in length and breadth; approximately 1-time P2 merus length and 6.5 times as long as broad; extensor margin with scale-like tubercles; flexor margin with four or five movable corneous spines on distal half; including distal pair. Dactyli slender; narrowing distally; approximately 0.5 times propodus length; flexor margin straight; with 12 or 13 movable corneous spines (spines on median part much larger) on the entire length; and distal spine closely appressed to claw; each corneous spine located on elevated base (Figure 4E). Pereopods without epipod. Egg diameter 2 mm (Figure 2D).
Remarks: The new species from CIR is the closest to Munidopsis guochuani Dong, Gan & Li, 2021 known from the seamount on the Caroline Plate, West Pacific Ocean. The new species from CIR can be differentiated from M. guochuani by carapace posterior margin ridged, with a row of spines on median part and tubercles laterally (Dong et al. 2021, Figure 21A), without a row of spines on median part (Figure 3A), the shape of the sternite 3 and 4 in the sternal plastron, and seven distinct plates in telson.
Genetic data. DNA sequencing for this species was successful for mtCOI gene (Accession numbers: COI: OP311614). The average K2P distance between the closely related M. guochuani (MT901058) and the CIR specimen was 0.07% for COI.
description: Published as part of Periasamy, Rengaiyan, Kurian, Palayil John & Ingole, Baban, 2023, Two new deep-water species of squat lobsters (Crustacea: Anomura: Galatheoidea) from the Central and Southwest Indian Ridge, pp. 165-178 in Zootaxa 5231 (2) on pages 167-170, DOI: 10.11646/zootaxa.5231.2.3, http://zenodo.org/record/7575272