Munidopsis opalescens Benedict, 1902

Guzman, Guillermo L. & Sellanes, Javier, 2015, A review of the Munidopsidae Ortmann, 1898 (Decapoda, Galatheoidea) in Chilean waters, including new records for the Southeastern Pacific, Zootaxa 4021 (2), pp. 282-306 : 292-295

Munidopsis opalescens Benedict, 1902

( Fig. 7 )

Restricted synonymy:

Munidopsis opalescens Benedict, 1902: 287 , fig. 31.— Haig, 1955: 41.— Retamal, 1981: 22, 23, fig. 99.— Wicksten, 1989: 315 (list).— Gorny, 1999: tab. 2.

Type locality. Collingwood strait, “Albatross” expedition stn N° 2781, Reina Adelaida archipelago, Magellan region, Chile (51°52’00”S, 73°41’00”W).

Other records. Collingwood Strait and Messier channel, Southern Chile ( Haig 1955; Gorny 1999; Wicksten 1989).

Distributional range. Chilean Patagonia and subantarctic Islands ( Haig 1955; Wicksten 1989; Gorny 1999).

New record. CBUCN 0 0 3867, 1 female, stn AGT 8 (36°00.23’S, 73°38.41’W, 922 m), “VG07” cruise, AGOR “Vidal Gormáz” (September 2007). MUAP (CD)-0342: 12 specimens “SeepOx” cruise; Inspire expeditions, 3 specimens.

Description. Rostrum long, about 2 times carapace length, armed with 3 lateral spines ( Fig. 7 a). Carapace almost oval, covered by spines and minute tubercles; lateral margin with strong spines; antennal spine tooth-like, not reaching the cornea; anterolateral spines strong, with minor submarginal spines ( Fig. 7 a); cervical groove depressed; gastric and cardiac regions at almost the same elevation; gastric region with many spines: 1 strong middle and 2 more anteriorly projecting spines anteriorly, 1 row of small posterior spines; cardiac region with strong medial spine projecting anteriorly; posterior margin with spines curved anteriorly. Abdomen armed with spines; second somite with 2 strong curved spines, third somite with four spines. Fourth somite without spines, with 2 mid tubercles. Fifth and sixth unarmed ( Fig. 7 b). Chelipeds long, almost 2 times carapace length, palm longer than fixed finger; armed on dorsal margin with almost 2 rows of spines, ventral margin and surface with minute tubercles ( Fig. 7 c); carpus with 3 rows of well-developed spines ( Fig. 7 d); merus with 3 row of spines on dorsal margin with strong spines; 2 other rows of spines, 1 medial, other ventral ( Fig. 7 e). Pereiopods subcylindrical, longer than carapace, reaching propodus of cheliped, armed with dorsal and other mid row ( Fig. 7 f). Sexual dimorphism present in shape of cheliped, females with more slender palm and fingers ( Fig. 7 g). Distal tip of dactyl of cheliped with longer tooth on inner side ( Fig. 7 h).

Remarks. Few differences compared to the original description were observed in some specimens studied here. The rostrum is armed with three or four irregularly placed lateral spines ( Benedict 1902). Some specimens were observed with an asymmetrical conformation of the rostral armature, with three spines on one side and four on the other, no scars were evident to explain this asymmetry as a loss of one spine. The chelipeds are slender, but more robust in some males.

These new records extend the distribution of the species by about 1700 km northwards up to central Chile.

Figures

FIGURE 7. Munidopsis opalescens Benedict, 1902, male cl 23.46 mm, MUAP (CD) - 0342: a – f: male, 23.46 mm cl; g, female cl 10.15 mm cl. a, dorsal view of anterior region of carapace; b, lateral view of abdomen; c, left cheliped; d, detail of carpus of cheliped; e, merus of left cheliped; f, third left pereiopod; g, left cheliped female; h, detail of tip of cheliped. Scale = 1 mm.