Munida euripa, 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 : 12-15

Munida euripa sp. nov.

urn:lsid:zoobank.org:act:386746FC-3E5F-4901-9727-938B3160B145

Fig. 4

Etymology

From the Greek, euripos, strait, channel, in relation to the Mozambique Channel.

Type material

Holotype

MADAGASCAR: ♂, 11.4 mm, MIRIKY, Stn CP3241, 14°30′ S, 47°27′ E, 6 Jul. 2009, 274– 325 m ( MNHN-IU-2014-13475 ).

Paratypes

MADAGASCAR: 4 ♂♂, 9.5–11.4 mm, 1 ov. ♀, 10.8 mm, 4 ♀♀, 7.6–9.5 mm, same data as for holotype (MNHN-IU-2010-793); 1 ♂, 7.5 mm, 1 ♀, 12.0 mm, MIRIKY, Stn CP3248, 14°50′ S, 46°57′ E, 340–446 m, 7 Jul. 2009 (MNHN-IU-2014-13603); 3 ♂♂, 9.6–12.4 mm, 1 ♀, 11.4 mm, MIRIKY, Stn CP3263, 15°34′ S, 45°44′ E, 287–450 m, 10 Jul. 2009 (MNHN-IU-2010-803); 22 ♂♂, 5.3–10.6 mm, 2 ov. ♀♀, 7.2–7.5 mm, 5 ♀♀, 5.6–8.7 mm, ATIMO VATAE, Stn CP3584, 25°29.80′ S, 44°15.64′ E, 203–210 m, 10 May 2010 (MNHN-IU-2014-19217); 1 ♀, 5.0 mm, ATIMO VATAE, Stn CP3614, 26°12.74′ S, 45°07.37′ E, 250–300 m, 14 May 2010 (MNHN-IU-2014-13604).

Description

CARAPACE. 1.2 times as long as broad, with numerous secondary striae between main transverse ridges. Dorsal ridges with dense short non-iridescent setae and numerous scattered long iridescent and nonplumose setae. Gastric region with 4 pairs of epigastric spines, longest pair behind supraocular spines. One parahepatic and one postcervical spine on each side. Frontal margins oblique. Lateral margins slightly convex. First lateral spine at anterolateral angle, moderately long, not reaching level of sinus between rostrum and supraocular spines; one small spine in front of anterior branch of cervical groove. Branchial margins with five spines. Rostrum spiniform, about 0.5 times length of remaining carapace, horizontal. Supraocular spines barely reaching midlength of rostrum and not reaching end of corneae, slightly convergent, directed slightly upwards.

STERNUM. Surface of thoracic sternites 4–5 numerous short striae; sternite 7 with granules on each lateral portion.

ABDOMEN. Anterior ridge of somite 2 with 8 spines; somites 2–4 each with 6 uninterrupted transverse ridges on tergite behind anterior ridge; somite 5 with short ridges; posteromedian margin of somite 6 straight.

EYES. Ocular peduncles as long as broad, maximum corneal diameter 0.4 distance between bases of anterolateral spines.

ANTENNULE. Article 1 with 2 well-developed subequal distal spines; two lateral spines, distal much longer than proximal and not exceeding distomesial spine.

ANTENNA. Article 1 with strong distomesial spine exceeding distal margin of article 2. Article 2 with distomesial spine exceeding antennal peduncle; distolateral spine slightly exceeding article 3. Article 3 unarmed.

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

P1. 3 times carapace length, with numerous long iridescent and plumose setae along mesial margins of articles. Merus 1.2 length of carapace, 2.0 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, 2.5 times as long as broad, with spines along mesial and dorsal sides. Palm 2.5 times as long as broad, with row of small dorsal spines; few spines along lateral and mesial margins. Fingers slightly longer than palm; fiXed and movable fingers each with one proXimal and one distal spine.

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 0.9 length of P2 merus, P4 merus 0.8 length of P3 merus); P2 merus 0.8 length of carapace, 6 times as long as broad, 1.4–1.5 times as long as P2 propodus; P3 merus 5.5 times as long as broad, 1.4–1.5 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 8–10 proXimally diminishing spines, and 1–2 distal 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 8–10 slender movable spines on P2–4. Dactyli slender, length 0.8–0.9 that of propodi; fleXor margin with 5–6 movable spinules, distal third unarmed, without a spinule at base of unguis; P2 dactylus 7.5 times as long as wide.

GENETIC DATA. COI, 16S, see Table 1 .

Remarks

Munida euripa sp. nov. belongs to the group of species having five spines on the branchial lateral margins of the carapace, the lateral parts of the thoracic sternite 7 with granules, and spines on the anterior ridge of the second abdominal somite. The new species is closely related to M. limula Macpherson & Baba, 1993 from Madagascar. These species differ in several features:

– The abdominal somites 2–3 have more transverse ridges (8) in the new species than in M. limula (4). – The distal spines of the antennular article 1 are subequal in M. euripa sp. nov., whereas the distomesial spine is clearly longer than the distolateral in M. limula .

– The Mxp3 merus has a distal spine in the extensor margin in M. limula , whereas this spine is absent in the new species.

– The dorsal side of the P1 palm has numerous spines in M. limula , whereas there is a few spines only in M. euripa sp. nov. The P1 movable finger has some spines along the proXimal half in M. limula , whereas there is a basal and terminal spine only in M. euripa sp. nov.

Munida euripa sp. nov. showed high divergence values with respect to the rest of the species analysed here, although genetic data of M. limula were unfortunately not available. The minimum values found for 16S were around 4% (with respect to M. tiresias Macpherson, 1994 , M. taenia Macpherson, 1994 or M. armilla Macpherson, 1994 , from New Caledonia and adjacent waters), and 5 or 6% when other species of the western Indian Ocean were compared, such as M. mesembria sp. nov., M. benguela , and M. shaula . These values rise to figures around or higher than 10% when data from COI sequences were taken into account: 11% with respect to M. mesembria sp. nov., and 15–16% for M. nesiotes and M. shaula , while the minimum found was with respect to M. armilla (9.1%). Among these species only M. taenia and M. armilla belong to the group of species having 5 spines on the branchial lateral margins of the carapace and the lateral parts of the thoracic sternites with granules. However, the new species can be easily distinguished from M. taenia and M. armilla by the following aspects:

– The front margin is transverse in M. taenia and M. armilla , instead of oblique in M. euripa sp. nov.

– M. taenia has numerous minute granules on the lateral parts of the thoracic sternites 6 and 7, whereas these granules are only present on sternite 7 of M. euripa sp. nov.

– The antennular article 1 has 2 subequal distal spines in M. euripa sp. nov., whereas the distomesial spine is longer than the distolateral in M. taenia and the distomesial spine is shorter than the distolateral in M. armilla .

– The movable finger of P1 has a row of spines along the mesial margin in M. taenia , whereas there is only a basal spine in M. euripa sp. nov.

– The P2–4 dactyli are more slender in M. euripa sp. nov. than in M. taenia and M. armilla . Furthermore, the fleXor margin has the distal third unarmed in M. euripa sp. nov., whereas there are spines along the entire fleXor margin in M. taenia and M. armilla .

Distribution

Madagascar, between 203 and 446 m.

Figures

Fig. 4. Munida euripa sp. nov., holotype, ♂, 11.4 mm (MNHN-IU-2014-13475), Madagascar. 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. Left P3, lateral view. I. Right P4, lateral view. Scale bar: A, E–F, H–I = 3.0 mm; B–D, G = 1.5 mm.