Munidopsis hystrix Faxon 1893

Munidopsis hystrix Faxon, 1893

(Fig. 14 a–h.)

Lectotype. MEXICO: Nayarit, off Tres Marias Islands, leg. USFC Steamer Albatross, Stn 3425, 18.iv.1891, 21.31666°N, 106.40000°W, 680 fms (1244 m): 1 M 17.1 mm (MCZ IZ-CRU-4549).

Paralectotypes. Same collecting data as lectotype: 7 M 8.8–18.7 mm, 1 ov. F 16.4 mm, 2 F 8.8–12.2 mm (MCZ IZ-163060).

Non-type specimens. MEXICO: western slope of Concepcion Canyon, Guaymas Basin, leg. Greg Rouse, Sigrid Katz, R/V Western Flyer, ROV Doc Ricketts dive D383 A2, 12.iv.2012, 26.88295°N, 111.658622°W, 823 m: 1 M 8.9 mm (SIO-BIC C14357). — MEXICO: leg. E/V Nautilus, ROV Hercules dive H1665, Stn NA092-058, 13.xi.2017, 19.24652°N 110.87116°W, 819 m: 1 M 15.3 mm (MCZ IZ-146311).

USA: California, leg. E/V Nautilus, ROV Hercules dive H1455, Stn NA066-148, 8.viii.2015, 33.66012°N, 118.56919°W, 556 m: 1 F 8.5 mm (MCZ IZ-73853). — USA: California, leg. E/V Nautilus, ROV Hercules dive H1460, Stn NA067-011, 15.viii.2015, 33.45408°N, 118.67693°W, 702 m: 1 juvenile 2 mm (MCZ IZ-73638). — USA: California, leg. E/V Nautilus, ROV Hercules dive H1542, Stn NA075-002, 25.vii.2016, 33.74604°N, 118.61636°W, 795 m: damaged specimen (MCZ IZ-139982). — USA: Santa Monica Mound, off California, leg. Emily McLaughlin, Jessica Pruitt, R/V Falkor, ROV SuBastian dive S0172, Slurp 4, 15.x.2018, 33.83468°N, 118.67614°W, 780 m: 1 F 11.20 mm (SIO-BIC C14031). — USA: Emery Knoll, off California, leg. Emily McLaughlin, Jessica Pruitt, R/V Falkor, ROV SuBastian dive S0175, Slurp 4, 17.x.2018, 33.03611°N, 118.39808°W, 665 m: 1 F 3.5 mm (SIO-BIC C14037). — USA: off San Diego, California, leg. Greg Rouse and students, R/V Robert Gordon Sproul SP1913, otter trawl, 14.vii.2019, 32.8093°N, 117.4673°W to 32.8739°N, 117.5154°W, 700 m: 1 ov. F 19.9 mm (SIO-BIC C14102), 1 M 20 mm (SIO-BIC C14111). — USA: Forty Mile Bank, off San Diego, California, leg. Greg Rouse, Kaila Pearson, E/V Nautilus, ROV Hercules dive H1845, cruise NA124, 3.xi.2020, 32.60044°N, 118.02825°W to 32.59787°N, 118.01624°W, 1111–650 m: 1 F 11.1 mm (SIO-BIC C14470).

Carapace spinose, dorsally covered by small spinules and setose scales, dorsal deep furrows, cervical grooves indistinct. Gastric region covered with spines, 1–2 pairs of well-developed epigastric spines, median cardiac spine well developed, preceded by a deep depression. Rostrum narrowly triangular, dorsally carinated, margin armed with 2–3 well-developed spines. Frontal margins concave. Orbit distinctly excavated, outer orbital angle delimited by antennal spine. Anterolateral angle armed with a strong spine. Anterior branchial margin armed with 3–4 welldeveloped spines; posterior branchial area dorsally armed with 3–4 pairs of well-developed spines, margin armed with small spines. Posterior carapace margin with 1–2 pairs of spines, preceded by a depression. Abdominal somites 2–4 with 2 transverse ridges, somite 2 armed with a pair of spines. Telson divided into 7 plates. Sternite 3 narrow, anterolateral angles produced, sternite 4 subtriangular. Eyes armed with dorsal spine, movable, epistomial spine absent. Article 1 of peduncle with well-developed dorsolateral and distolateral spines. Article 1 of antenna with distolateral spine. Mxp3 merus 0.5–0.6× longer than ischium, subrhomboidal in lateral view. P1 slender, elongate; meri and carpi with well-developed spines on all surfaces, fixed finger without denticulate carina on distolateral margin. P2–4 slender, spinose; dactyli slender, curving, flexor margin with teeth only at distal-half margin. Epipods absent from all pereopods.

Galapagos Islands, Perú, Gulf of California, Baja California and California, from 436- to 1244-m depth.

COI, 16S rRNA and 28S rRNA.

Munidopsis hystrix belongs to the group of species having a frontal margin with a delimited orbit, movable eye with small median spine projecting from upper surface, the abdomen armed with spines and the telson composed of 7–8 plates. This group of species includes M. hystrix, M. opalescens and M. margarita Faxon, 1893 from the East Pacific. These three species are morphologically and genetically similar. Differences relating to this complex are described in Remarks of M. margarita.