Emerita pangandaran, Farajallah & Hanim & Putri & Wardiatno, 2025

Farajallah, Achmad, Hanim, Nisfa, Putri, Vinna Windy & Wardiatno, Yusli, 2025, Two mole crab species of Emerita Scopoli, 1777 (Decapoda: Anomura: Hippidae) from Java Island, Indonesia, with description of a new species, Zootaxa 5631 (3), pp. 509-520 : 514-518

Emerita pangandaran sp. nov.

Zoobank Taxon registration urn:zoobank.org:act:D9622937-EAA7-4094-B0DC-7384EF19F20D

( Figs. 3–5 )

Holotype. MZB.Cru.5338, male (CL 18.3 mm), Pangandaran Beach , Pangandaran Regency, West Java Province, Indonesia, 7°42.185'S, 108°39.375'E, intertidal, coll. Nisfa Hanim, 7 October 2020.

Paratypes. MZB.Cru.5339, 1 female (CL 35.0 mm), Pangandaran Beach , Pangandaran Regency, West Java Province, Indonesia, 7°42.185'S, 108°39.375'E), coll. Nisfa Hanim and Achmad Farajallah, 22 August 2019 ; MZB. Cru.5340, 10 females (CL 15.1–32.4 mm), Sodong Beach , Cilacap Regency, Central Java Province, Indonesia, 7°41.6473'S, 109°11.3026'E, intertidal, coll. Achmad Farajallah and Dyah Perwitasari, 4 October 2020 .

Diagnosis. CL up to 35 mm. Carapace anterolateral margin crenulate. First pereiopod dactylus with 4 or 5 distinct spines on inner margin (including terminal spine), terminal spine shorter than others; outer margin crenulated but without distinct spines.

Description of holotype. CL 18.3 mm, body almost cylindrical. Carapace frontal margin trilobate, all lobes sharply triangular, median lobe shorter than lateral lobes, separated by wide U-shaped sinus; anterolateral margin crenulate ( Fig. 4a ); dorsal surface covered with prominent transverse ridges ( Fig. 3 ); lateral margin serrate on anterior half, serrate appearance formed by minutely setose pits; posterolateral margin rounded.

Ocular peduncle elongated, slender, reaching tip of second antennal segment ( Fig. 4a ). Antennular flagellum composed of 27–30 articles. Second antennal segment with three sharply pointed, large spines distally, median spine longest.

Third maxilliped merus rectangular, 1.50–1.63 times as long as greatest width; outer anterolateral angle rectangular; anteromesial lobe distinct, distally rounded ( Fig. 4b ).

First pereiopod dactylus broadly ovate in general outline, 1.85–2.08 times as long as greatest width, with 1 terminal spine; inner margin with 3 or 4 distinct horny spines; outer margin crenulated but without distinct spines ( Fig. 4c ). Dactyli of second and third pereiopods falcate, distally subacute, thin.

Telson triangular, slightly convex on lateral margins, rounded on distal margin.

Variation. Specimens MZB.Cru.5338 and MZB.Cru.5339 from Pangandaran have four or five distinct horny spines on the inner margin, including the terminal spine, and the antennular flagellum consists of 27–30 articles. Specimen MZB.Cru.5340 from Cilacap has the first pereiopod dactylus with one or two spines on the inner margin (perhaps another spine was broken), and the antennular flagellum has 39 or 40 articles.

Natural history. Emerita pangandaran sp. nov. is found in the swash zone area of beach which has coarse white sand.

Etymology. The new species name is derived from the locality and is a noun in apposition.

Comparison. Emerita pangandaran sp. nov. with its putative sister species, Emerita emeritus , differ from other species of the genus by the combination of the number of spines on the inner margin of the dactylus of the first pereiopod, the length of the dactylus of the first pereiopod being less than twice the width, the dactylus of the first pereiopod distally bearing a terminal spine, and the frontal lobes are distally acute. Differences between the two species are in the presence of a spine on the outer margin of the dactylus of the first pereiopod and the armature of the anterior margin of the carapace ( Table 4 ). The general differences between the new species and the other four species in the phylogeny, are, in E. analoga ( Stimpson, 1857) , E. brasiliensis Schmitt, 1835 , and E. talpoida ( Say, 1817) , that the dactylus of the first pereiopod is distally obtuse (without terminal spine), and in E. portoricensis Schmitt, 1835 , the frontal lateral lobes are obtuse ( Schmitt 1935). In species of the genus Emerita the dactylus of the first pereiopod is flat, unlike those of the genus Hippa which have a dactylus on the first pereiopod that is spiniform.

Figures

FIGURE 3. Emerita pangandaran sp. nov., holotype male, MZB Cru 5338, CL 18.3 mm, dorsal view.

FIGURE 4. Emerita pangandaran sp. nov., holotype male, CL 18.3 mm: a, frontal lobes of carapace, dorsal view; b, merus of right third maxilliped, outer view; c, dactylus of left first pereiopod, dorsal view. Scale bars: 1 mm.

FIGURE 5. Emerita pangandaran sp. nov., holotype male, CL 18.3 mm: a, second segment of left antenna, dorsal view; b, distal portion of left pereiopod I, dorsal view; c, carapace and first abdominal somite, lateral view; d, right third maxilliped, outer view. e, right third maxilliped, inner view. Scale bars: 1 mm.