Schizocuma spinoculatum (Jones, 1984)

Corbera, Jordi, 2012, Rare and new cumaceans (Crustacea, Peracarida) from the southern margin of the Cap Ferret Canyon (Bay of Biscay), ZooKeys 235, pp. 73-85 : 81-82

Schizocuma spinoculatum (Jones, 1984) Fig. 5

Cumella spinoculata - Jones 1984, pp. 219-220, fig. 10.

Schizocuma spinoculatum - Watling 1991, p. 755.

Material examined.

Schizocuma spinoculatum : ESSAIS II, stn TS13, 44°34.19'N, 2°16.18'W, 1097-1099 m, 17/05/89, 7 pread. females, 2 imm. males, 1 ad. male.

Schizocuma molosa (Zimmer, 1907): BENTART 06; stn 30, 69°58'24"S, 87°26'54"W, 1798-1799 m, 27/01/2006, 1 ad. male, 1 imm; stn 31, 69°57'46"S, 87°22'08"W, 1395 m, 29/01/2006, 2 imm. females, 1 ad. male; stn 38, 69°15'11"S, 80°12'11"W, 1339-1343 m, 5/02/2006, 1 imm. female.

Remarks.

When Jones (1984) described Schizocuma spinoculatum , he had already noted its strong resemblance to Schizocuma molosa , but then the latter species was only known by a single partially broken specimen ( Zimmer 1907, 1913). Comparison of the material collected in the Bay of Biscay with those obtained during the Bentart 06 cruise in the Bellingshausen Sea ( Corbera et al. 2009) enabled us to identify differences between the two species. On the tip of pseudorostrum of Schizocuma molosa there are a couple of spines (Fig. 5C), one on the upper angle and another just bellow the siphon; the first one is absent in Schizocuma spinoculatum (Fig. 5A). The hinder dorsal third of the carapace of Schizocuma molosa also has a pair of forward curving spines and long simple setae while Schizocuma spinoculatum has only a pair of simple setae. Moreover, the carapace is more elongated in Schizocuma molosa than in Schizocuma spinoculata (length-height ratio: 1.8 vs 1.5), which is also true of the uropod peduncle (peduncle-endopod length ratio: 1.8-1.9 vs 1.5) (Fig. 5B, D). All of these differences can be observed both in males and in females, which gives support to the validity of both species.