dcsimg

Description

provided by NMNH Antarctic Invertebrates

Austropallene tibicina, sp. nov. (Text-figs. 7 and 8).

Occurrence. – Station 220, off Cape Adare, 45-50 fathoms; 3 females, 2 males (incl. Holotype).

Description. – Resembling A. brachyura in general form, but more slender and with the spurs of the body and legs much larger.

Cephalic segment nearly half the total length of the trunk, anterior dilatation about two and a half times the diameter of the neck. Ocular tubercle low, obtuse, much smaller in diameter than the neck, eyes well-separated, reddish.

Lateral processes separated by intervals of at least their own diameter, the first with one, the others with a pair of large distal spurs, and each also with a small conical tubercle in the middle of the distal margin. The lateral processes and their spurs are more elongated in the male than in the female.

Proboscis contracted, about the middle of its length, to a slender, downwardly-curved tube, with a conspicuous brush of setae on the three terminal lips.

Abdomen relatively a little larger than in A. brachyura, directed obliquely upwards.

Chelophores slender, the scape more (male) or less (female) than four times as long as thick, shorter than the proboscis. Chelae not more than two-thirds the length of the scape, moveable finger strongly arched, toothless, shorter than the palm, immovable finger extending far beyond it, curved only at the tip, with two blunt tubercles between which the tip of the immovable finger fits; both fingers sharply pointed.

Oviger of male with fifth segment twice as long as fourth, bearing a short lateral process at its distal end.

Legs slender. First coxa of each with a pair of lateral spurs which, at least in the male, exceed the diameter of the segment. Second coxa three (female) or four (male) times as long as the first and a little less or more than half as long as the femur, gently curved and dilating distally; on the dorsal surface are two rows of tubercles, those of the posterior row the larger, and two or three of them in the male forming large spurs. Femur longer by one-fourth than the first tibia and subequal to the second.

Surface of body smooth, the legs spinous, especially the distal segments.

Measurements, in mm.

Holotype

Male

Female

Length of proboscis

1.68

1.44

Diameter of proboscis at base

0.36

0.36

Diameter of proboscis near tip

0.12

0.12

Length of cephalon

0.88

0.76

Greatest width of cephalon

1.00

0.92

Width of neck

0.4

.038

Length of trunk

2.6

2.16

Width between first and second lateral processes

0.44

0.4

Width across second lateral processes

2.08

1.44

Third right leg –

First coxa

0.48

0.44

Second coxa

1.92

1.36

Third coxa

0.72

0.48

Femur

3.72

3.04

First tibia

3.0

2.56

Second tibia

3.6

2.88

Tarsus and propodus

1.32

1.04

Claw

0.72

.064

Remarks. – This species is allied to A. brachyura, especially in the armature of spurs on the lateral processes and proximal segments of the limbs and in the shortness of the abdomen. It differs from that species, amongst other characters, in the form of the proboscis with its slender distal part and conspicuous apical brush, and in the long and sharply pointed immovable finger of the chela.” (Calman 1915, p.39-41)

Habitat

provided by World Register of Marine Species
shelf

Reference

van der Land, J. (ed). (2008). UNESCO-IOC Register of Marine Organisms (URMO).

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WoRMS Editorial Board
contributor
Jacob van der Land [email]