Munida austrina, Macpherson & Rodríguez-Flores & Machordom, 2017

Macpherson, Enrique, Rodríguez-Flores, Paula C. & Machordom, Annie, 2017, New sibling species and new occurrences of squat lobsters (Crustacea, Decapoda) from the western Indian Ocean, European Journal of Taxonomy 343, pp. 1-61 : 6-9

Munida austrina sp. nov.

urn:lsid:zoobank.org:act:F1C708C0-54BD-4874-B484-45A224C953B0

Fig. 2

Etymology

From the Latin, auster, south, in relation to area of species distribution.

Type material

Holotype

MOZAMBIQUE: ♀, 4.6 mm, MAINBAZA, Stn CC3175, 25°32.70′ S, 33°12.09′ E, 155–165 m, 17 Apr. 2009 ( MNHN-IU-2014-13478 ).

Paratype

MOZAMBIQUE: 1 ♂, 7.0 mm, 7 ♀♀ 3.0– 8.1 mm, MAINBAZA, Stn CC 3175, 25°32.70′ S, 33°12.09′ E, 155–165 m, 17 Apr. 2009 (MNHN-IU-2014-13504).

Description

CARAPACE. 1.2 times as long as broad, with some secondary ridges between main transverse ridges. Dorsal ridges with dense short non-iridescent setae and few scattered long iridescent and non-plumose setae. Gastric region with 5–6 pairs of epigastric spines, longest pair behind supraocular spines. One small parahepatic, one postcervical and one branchial dorsal spines on each side. Frontal margins transverse. Lateral margins slightly convex. First lateral spine at anterolateral angle, long, barely reaching level of sinus between rostrum and supraocular spines; one small spine in front of anterior branch of cervical groove; end of anterior branch of cervical groove with tuft of iridescent setae. Branchial margins with five spines. Rostrum spiniform, about 0.6 times length of remaining carapace, horizontal, dorsally carinated. Supraocular spines reaching midlength of rostrum and not reaching end of corneae, subparallel and slightly upwards directed.

STERNUM. Surface of thoracic sternites smooth, with a few short striae on sternites 3 and 4; distal margin of sternite 4 transverse, broadly contiguous to sternite 3.

ABDOMEN. Anterior ridge of somite 2 unarmed; somites 2–5 each with 3–4 transverse ridges on tergite behind anterior ridge; posteromedian margin of somite 6 straight.

EYES. Ocular peduncles as long as broad, maximum corneal diameter 0.5 distance between bases of anterolateral spines.

ANTENNULE. Article 1 with 2 well-developed distal spines, distomesial spine slightly longer than distolateral; two lateral spines, distal much longer than proximal and exceeding distomesial spine.

ANTENNA. Article 1 with strong distomesial spine barely exceeding distal margin of article 2. Article 2 with distomesial spine reaching end of antennal peduncle; distolateral spine reaching end of article 3, minute spine at mid-length mesially. Article 3 unarmed.

MXP3. Ischium with small distal spine on fleXor margin. Merus shorter than ischium; fleXor margin with 2–3 spines, proximal spine stronger than others; extensor margin with distal spine. Carpus unarmed.

P1. 2.3 times carapace length, with some long iridescent and plumose setae along mesial margins of articles. Merus 0.9 length of carapace, 2.2 times as long as carpus, with some dorsal spines; distal spines strong, distomesial spine not reaching proximal third of carpus. Carpus 0.7–0.8 length of palm, 1.5 times as long as broad, with spines along mesial and dorsal sides. Palm 1.9 times as long as broad, with row of small dorsal spines; few spines along lateral margin continuing with 4–5 spines along lateral margin of fiXed finger; one mesial row of spines. Movable finger with proXimal spine only. Fingers slightly longer than palm.

P2–4. Moderately long and slender, with numerous plumose and iridiscent setae along extensor margin of articles. P2 2.0–2.1 times carapace length. Meri shorter posteriorly (P3 merus 0.8 length of P2 merus, P4 merus 0.8 length of P3 merus); P2 merus 0.7 length of carapace, 6 times as long as broad, 1.5 times as long as P2 propodus; P3 merus 5 times as long as broad, 1.2 times as long as P3 propodus; P4 merus 4.5 times as long as broad, 1.2 times length of P4 propodus. Extensor margins of P2–3 meri with row of 7–8 proXimally diminishing spines, and 1–2 spines on P4; fleXor margins distally with some spines followed proximally by several eminences; lateral sides unarmed. Carpi with 2–3 spines on extensor margin of P2–4; lateral surface with several granules sub-paralleling eXtensor margin on P2–4; fleXor margin with distal spine. Propodi 6.0–6.5 (P2–3)–5.5 (P4) times as long as broad; extensor margin unarmed; fleXor margin with 9–10 slender movable spines on P2–4. Dactyli slender, length 0.8–0.9 that of propodi; fleXor margin with 5–7 movable spinules, distal third unarmed, without a spinule at the base of the unguis; P2 dactylus 8 times as long as wide.

GENETIC DATA. COI, see Table 1 .

Remarks

Munida austrina sp. nov. belongs to the group of species having five spines on the branchial lateral margins of the carapace, thoracic sternites without granules, large eyes, and the anterior ridge of the second abdominal somite unarmed. The new species is closely related to M. mesembria sp. nov. (see below under the remarks of that species). However, the minimum divergence for COI found was in respect to M. notata Macpherson, 1994 , from New Caledonia and adjacent waters (9.1%). Munida austrina sp. nov. and M. notata differ in the following aspects:

– The distomesial spine of the antennal article 1 barely exceeds the antennal article 2 in M. austrina sp. nov., whereas this spine clearly overreaches the antennal article 3 in M. notata . The distomesial spine of the antennal article 2 clearly exceeds the antennal peduncle in M. notata , whereas this spine reaches the end of the antennal peduncle in the new species.

– The movable finger of P1 has a proXimal spine only in M. austrina sp. nov., instead of a row of spines along the mesial margin in M. notata .

Distribution

Mozambique, between 155 and 165 m.

Figures

Fig. 2. Munida austrina sp. nov., holotype, ♀, 4.6 mm (MNHN-IU-2014-13478), Mozambique. A. Carapace and abdomen, dorsal view. B. Sternal plastron. C. Cephalic region, showing antennular and antennal peduncles, ventral view. D. Right Mxp3, lateral view. E. Right P1, dorsal view. F. Right P2, lateral view. G. Dactylus of right P2, lateral view. H. Right P3, lateral view. I. Right P4, lateral view. Scale bar: A, E–F, H–I = 1.0 mm; B–D, G = 0.5 mm.