Munidopsis cortesi, Rodríguez-Flores & Seid & Rouse & Giribet, 2023

Rodríguez-Flores, Paula C., Seid, Charlotte A., Rouse, Greg W. & Giribet, Gonzalo, 2023, Cosmopolitan abyssal lineages? A systematic study of East Pacific deep-sea squat lobsters (Decapoda: Galatheoidea: Munidopsidae), Invertebrate Systematics 37 (1), pp. 14-60 : 51-54

Munidopsis cortesi sp. nov.

( Fig. 20 g, h , 16 a–j .)

Zoobank: urn:lsid:zoobank.org:act:FDC547F3-F3AF-4E15-B2E4-87839 72CBC61

Material examined

Holotype. COSTA RICA: Jaco Summit, leg. Greg Rouse, Allison Miller, R/V Falkor, ROV SuBastian dive S0213, Slurp 4, 6.i.2019, 9.17402°N, 84.79990°W, 742 m: ov. F 5.2 mm (tissue SIO-BIC C13902 ex MZUCR 3761-01).

Etymology

Named for Prof. Jorge Cortés Núñez, Universidad de Costa Rica, for his invaluable collaboration on deep-sea research and his efforts to create awareness of the deep regions of Costa Rica. We honour Prof. Cortés’ academic retirement after more than 40 years of research in marine biodiversity and ecology, and we celebrate his continued dedication to promoting ocean conservation.

Diagnosis

Carapace pubescent, dorsally smooth, with deep dorsal furrows, cervical grooves indistinct. Rostrum broadly triangular, trifid distally. Frontal margins concave. Orbit distinctly excavated, outer orbital angle with a strong spine. Anterolateral unarmed. Branchial unarmed. Abdominal somites 2–4 armed with posterolateral teeth, abdominal somite 3 armed with 4 teeth. Telson divided into 7 plates. Sternite 3 anterolaterally rounded, anterior margin with median serrated shallow notch flanked by 2 lobes, sternite 4 subtriangular. Eyes unarmed, movable, epistomial spine absent. Article 1 of antennule with dorsolateral and distolateral spines. Article 1 of antenna with well-developed distomesial spine. Mxp3 merus subrhomboidal in lateral view. P1 slender, pubescent, fixed finger without denticulate carina on distolateral margin. P2–4 stout, pubescent; meri armed with acute teeth on flexor and extensor margins, propodi flattish in cross-section; dactyli slender, curving, flexor margin with cuticular teeth along all margins decreasing proximally. Epipods absent from all pereopods.

Description

Carapace

1.2× longer than wide; moderately convex from side to side; hirsute, dorsally unarmed, densely covered in short, fine setae, long distally curved setae on gastric region. Regions well delineated by deep furrows, cervical grooves indistinct. Gastric region slightly elevated. Posterior cardiac region elevated and constricted by lateral furrows, forming notches; posterior margin posteriolaterally armed with small teeth, preceded by deep transverse depression. Rostrum broad, width 0.3× anterior width of carapace, 0.4× carapace length; trifid distally; apex directed slightly upwards; lateral proximal margin weakly oblique, 1.4× as long as broad. Frontal margin concave behind ocular peduncle, antennal (outer orbital) spine strong. Lateral margins unarmed; slightly convex; widest at midlength, anterolateral angle unarmed. Pterygostomian flap densely covered with acute teeth, viewed in dorsal view, anterior margin blunt, unarmed.

Sternum

1.2× longer than broad, maximum width at sternite 5. Sternite 3 broad, 2.9× wider than long, anterolaterally rounded, anterior margin with median serrated shallow notch flanked by 2 lobes. Sternite 4 narrowly elongated anteriorly; surface depressed in midline, smooth; greatest width 2.7× that of sternite 3 and 2.0× wider than long.

Abdomen

Tergites with short, fine, dense setae; tergites 2–4 armed with posterolateral teeth; tergite 3 with elevated ridge, armed with 4 teeth; tergites 3–6 without elevated ridges; tergite 6 with posterior margin not produced. Telson composed of 7 plates, as wide as long.

Eye

Ocular peduncle unarmed; surface densely setose, movable, partially concealed by rostrum. Cornea subglobular, slightly wider than peduncle.

Antennule

Article 1 of peduncle with subequal dorsolateral and distolateral spines, distolateral spine bifid; distomesial margin with 2 pairs of blunt processes, distal surface dentate; distolateral margin armed with one spine.

Antenna

Peduncle exceeding eye; Article 1 with distomesial spine not reaching end of article 2, distolateral angle rounded. Articles 2–3 with well-developed distolateral spine, distomesial spine smaller. Article 4 unarmed. Flagellum longer than carapace.

Mxp3

Merus with 2 large spines along flexor margin, proximal larger than distal; small distal spine on extensor margin. Ischium longer than wide, with distal flexor and extensor spines. Crista dentata finely denticulate. Dactylus, propodus and carpus unarmed.

P1

Slender, densely covered in short, fine setae and long setae, 1.4× longer than carapace. Merus 2.4× carpus length, with some stout distal spines. Carpus 2.4× longer than broad, with some stout distal spines. Palm unarmed, slender, slightly longer than carpus, 2.6× longer than broad. Fingers unarmed, 0.85× longer than palm, opposing margins nearly straight, not gaping, spooned, fixed finger without denticulate carina on distolateral margin.

P2–4

Stout, densely covered in short fine setae and some long distally curved setae, cylindrical in cross-section, slightly decreasing in size posteriorly. P2 merus stout, 0.55× carapace length, nearly 3.1× longer than high and 1.3× length of P2 propodus. P2–4 meri decreasing in length posteriorly (P3 merus 0.7× length of P2 merus, P4 merus 0.9× length of P3 merus); extensor margin of P2–4 meri with acute teeth along entire border, distal part trianguloid; flexor margin with acute teeth along entire border, distal strongest; carpi P2–3 with two thick teeth on extensor margin, distal strongest, flexor margin unarmed; P2–4 propodi 4.3–4.4× as long as high, flattish in cross-section, unarmed; dactyli 0.7–0.9× length of propodi; distal claw short, moderately curved; flexor margin distally curved, with 6–8 dactylar teeth decreasing in size proximally, each with slender corneous spine, ultimate tooth at midlength between penultimate tooth and dactylar angle.

Epipods

Absent from pereopods.

Colouration

Carapace, abdomen and pereopods orange and brownish. Ocular orbits orange.

Distribution

Costa Rica at 742-m depth.

Genetic data

COI, 16S rRNA and 28S rRNA.

Remarks

Munidopsis cortesi sp. nov. belongs to a group of species sharing a flattened, distally trifid rostrum and unarmed carapace surface, and lacking pereopodal epipods. This group includes M. acuminata Benedict, 1902 from off South Carolina, north-western Atlantic; M. alcocki Ahyong, 2014 from the Indian Ocean, M. aurantia Lin & Chan, 2011 from Taiwan, M. kareenae Ahyong, 2013 from New Zealand, M. modesta Benedict, 1902 from Galapagos Islands, M. nias Ahyong, 2014 from the eastern Indian Ocean, M. pubescens Macpherson, 2007 from Madagascar, M. serricornis from the North Atlantic Ocean, M. tuerkayi Macpherson, Beuck & Freiwald, 2016 from the Caribbean Sea and M. treis Ahyong & Poore, 2004 from the West Pacific Ocean.

This new species is very different and easily distinguished from the other species of the group by the following characters:

• The new species has an unarmed anterolateral angle of the carapace and unarmed carapace margins whereas the other species have at least the anterolateral margin armed.

• The new species have acute teeth on the pterygostomian flap surface whereas these teeth are absent in the other species.

• The new species have acute teeth on the flexor and extensor margins of the meri of P2–4, whereas these teeth are absent in the other species, and in all of these, the flexor margins of the meri are unarmed.

Figures

Fig. 20. Line diagrams of Munidopsis cortesi sp. nov., ov. F 5.2 mm, holotype (MZUCR 3761-01), Costa Rica. (a) Carapace and abdomen, dorsal view. (b) Carapace and abdomen, lateral view. (c) Sternal plastron. (d) Telson. (e) Cephalic region, showing antennular and antennal peduncles, ventral view. (f) Left Mxp3, lateral view. (g) Right P1, dorsal view. (h) Right P2, lateral view. (i) Right P3, lateral view. (j) Right P4, lateral view. (k) Right P4 dactyli, lateral view. Scale bars: 1 mm.

Fig. 16. Line diagrams of Munidopsis nautilus sp. nov., ov. F 11.0 mm, holotype (MCZ IZ-70119), Ecuador: Galapagos. (a) Carapace and abdomen, dorsal view. (b) Sternal plastron. (c) Telson. (d) Cephalic region, showing antennular and antennal peduncles, ventral view. (e) Left Mxp3, lateral view. (f) Right P1, dorsal view. (g) Right P2, lateral view. (h) Right P3, lateral view. (i) Right P4, lateral view. (j) Right P4 dactyli, lateral view. Scale bars: 1 mm.