FSFL EM399, EM400 (2♂♂, 2 ovig. ♀♀-53°32′S, 60°10′W, 1,033 m deep; Aug. 5, 1978). Total length from tip of rostrum to tip of telson, 11-13 cm in 4 specimens at hand.
Description:
Body strongly compressed, carapace being thin and widening posteriorly; lateral surface with a longitudinal, weakly curved blunt ridge originated from hepatic region; branchiostegal spine small and placed slightly behind anterior margin of carapace, being followed by a blunt, short submarginal ridge; no antennal spine, but 2 angular projections present on anterior margin of carapace. Rostrum directed obliquely upward and sharply pointed, being placed at some distance behind anterior margin of carapace; dorsal margin of rostrum strongly crested, without teeth, and extended onto carapace almost to its posterior margin. First 2 pereiopods chelate, with pectinate cutting edges as usual; palm of first pair thick and longer than fingers, but in second pair palm is narrowing distally and as long as fingers; lower margin of each merus armed with some spines with irregular intervals in first pair, and with more than 10 in second pair. Abdomen carinated dorsally, each segment having a shallow transverse furrow at anterior third. Telson dorsally grooved throughout its length and deeply incised from its posterior margin and fringed with horny spines.
Distribution:
Mainly known from Chilean coast, ranging from the vicinity of 41° S through the Straits of Magellan to off the Falkland Islands; 300-470 m deep and now extended downward to 1,033 m deep, but Zerenkov (1968) recorded this species from the Darke Passage, 3,065-3,669 m deep.
Remarks:
As pointed out by Holthuis (1952), it is quite questionable whether the original material is homogenous or not. Of the two specimens, one from Patagonia was selected to be the lectotype by him, so that there is no doubt about the scientific name of the specimens at hand. The other specimen from Sagami Bay, Japan, must be examined in detail.
(Masatsune TAKEDA)
Distribution of Pasiphaea acutifrons in Patagonia.