Munidopsis quadrata Faxon, 1893
(Fig. 8)
Restricted synonymy:
Munidopsis quadrata Faxon, 1893: 188 .— Schmitt, 1921: 170, fig. 109.— Luke, 1977: 26 (list).— Wicksten, 1989: 3, 15 (list).— Baba, 2005: 293.
Type locality. Stn 3424 “Albatross” Expedition (Faxon 1983)
Distributional range. from Tres Marias up to 24°56’N, Gulf of California, Mexico; from Wilmington and Los Coronadas Islands, south of California to Charlotte Islands, Canada (Ambler 1980; Wicksten 1989; Hendrickx 2003); Arica, (18°44.7’S, 70°40.7’W) Luke 1977; Antofagasta to south Constitución (this study)
Bathymetric range. 245–1547 m
New records. MUAP (CD)-04111, 1 male, stn AGT-5 (22°48.02’S, 70°36.71’W, off Antofagasta, 1351 m), “ PUCK ” expedition, RV “Sonne”, April–May 2001; CBUCN 0 0 3863, 1 male, stn AGT 4 (34°42.48’S, 72°23.05’W, 923 m), “VG07” cruise AGOR “Vidal Gormáz”, September 2007; CBUCN 0 0 3866, 1 ovigerous female, stn AGT 8 (36°00.12’S, 73°38.24’W, 922 m), VG07 cruise AGOR “Vidal Gormáz”, September 2007.
Description. Rostrum widely triangular, about half carapace length, curved upward, flattened dorsally. Carapace subrectangular covered with tubercles; without antennal and lateral spines; cervical groove well developed, gastric and cardiac regions elevated (Fig. 8 a). Second to fourth abdominal somites dorsomedially armed with strong, tooth-like tubercle, curved and anteriorly projecting (Fig. 8 b); pleuron of second somite and partially on third somite with tubercles. Chelipeds as long as 2 times carapace length, slightly cylindrical, surface with tubercles, dactyl one and one-half times length of palm (Fig. 8 c). Pereiopods long, first reaching basal part of cheliped, surface with tubercles, more dense on merus and carpus (Fig. 8 d), same ornamentation on carpus (Fig. 8 e) and merus (Fig. 8 f).
Remarks. This species is very characteristic because of the quadrangular shape of carapace. No differences compared to the original descriptions were observed.
The presence of authigenic carbonates at the sites where the last two specimens were collected indicates the presence of methane seeps nearby. These new records for Chile extend the range of the species by about 1750 km south, to 36°00.12’S (southwest off Constitución, Chile).