Catherinum tortilum ( Zevina, 1973 )

Poltarukha, Oleg P. & Mel’Nik, Vyacheslav F., 2012, New records of deep-sea barnacles (Cirripedia: Thoracica: Scalpelliformes) from the Clarion-Clipperton region, Pacific Ocean, Zootaxa 3297, pp. 34-40 : 38

Catherinum tortilum ( Zevina, 1973)

Figure 3

Scalpellum (Mesoscalpellum) tortilum Zevina, 1973: 1003 , figs 12–16.

Catherinum tortilum . — Zevina, 1978: 1348. — Zevina, 1981b: 247, fig. 184. — Young, 2007: 51, 69, fig. 63.

Material examined. Mg-1217, 1 specimen, stn 8545 (12°.95168N, 134°.61242W), 07 Aug. 2007, depth 4877m; Mg-1218, 1 juv. specimen, stn. 8713 (13°.4514 N, 133°.53807 W), 01 Jan. 2011, depth 4872m.

Diagnosis. 14 fully calcified capitular plates; cuticle without setae. Upper latus quadrangular. Umbo of inframedian latus laterally displaced. Umbo of rostrolatus protruding beyond carina.

Description. Capitulum white, elongate; cuticle without setae. Capitular plates with growth lines thin. Tergum triangular; umbo apical, apex and basal angle curved; occludent margin slightly convex. Scutum with apex recurved, extending over tergum. Carina regularly arched, roof flat, lateral margins narrowing basally. Upper latus quadrangular; apex acute, recurved; scutal margin distinctly concave; tergal margin convex; other margins almost straight. Carinolatus higher than wide, pentagonal; umbo protruding beyond carina; plates interdigitating under carina, forming small interlock. Inframedian latus distinctly curved; umbo laterally displaced. Rostrolatus with umbo in upper rostral angle, umbo protruding beyond tergum. Rostrum small, triangular. Peduncle short, approximately one quarter length of capitulum, covered by scales. Labrum bullate, crest with small irregular teeth. Labial palp acuminate, with few setae. Mandible with 3 acute teeth, 8 small acute denticles at lower angle. Maxilla I narrow, cutting edge slightly twisting; 2 large setae above slight notch; notch with 2 small teeth; group of medium-sized setae below notch. Maxilla II heart-shaped, covered with setae; maxillary gland long, projecting prominently. Cirrus I with rami unequal; outer ramus slender, longer, 12-segmented, inner ramus broader, short, 8- segmented; both rami covered by plumose acinaciform setae. Cirrus II with outer ramus 17-segmented, inner ramus 18-segmented. Cirrus III with outer ramus 23-segmented, inner ramus 24-segmented. Cirrus IV with outer ramus 24-segmented, inner ramus 25-segmented. Cirrus V with outer ramus 25-segmented, inner ramus 26- segmented. Cirrus VI with outer ramus 26-segmented, inner ramus 26-segmented; medial segments of cirrus VI clothed with 4 pairs of setae on ventral margin of inner ramus, 5 pairs of setae on ventral margin of outer ramus. Caudal appendage 7-segmented, size equal to protopodite of cirrus VI.

Distribution. Indian Ocean: off South Africa (29°42’S, 33°19’E) and India (5°36’N, 82°23’E); Pacific Ocean, Clarion-Clipperton region; depth 2760–4877 m.

Remarks. This is the first record of C. tortilum from the Pacific Ocean. Previously, this species was known only from the Indian Ocean ( Zevina 1973; Young 2007).

Figures

FIGURE 3. Catherinum tortilum (Zevina, 1973). A. Left side view, B. External view from rostral side, C. External view from carinal side, D. Labrum, E. Labial palp, F. Mandible, G. Maxilla I, H. Maxilla II, I. Caudal appendage, J. Juvenile specimen left side view.