A new species of hydrothermal vent stalked barnacle Vulcanolepas (Scalpelliforms: Eolepadidae) from the North Fiji Basin, Southwestern Pacific Ocean Author Chan, Benny K. K. Author Ju, Se-Jong Author Kim, Se-Joo text Zootaxa 2019 2019-02-28 4563 1 135 148 journal article 28152 10.11646/zootaxa.4563.1.7 7df393d6-691e-4b9a-9cb6-fd28189409ba 1175-5326 2601027 3BB9131A-4368-46F6-B8DC-CC899B98E59D Vulcanolepas fijiensis sp. nov. ( Figures 3–7 ) Material examined. Holotype . NIBR-IV0000830370 . North Fiji Basin (16° 59' 3848” S, 173° 54' 9067” E; 05.12.2016 ; depth 1988 m ); collected using ROV ( ROPOS , Canadian Scientific Submersible Facility); coll. W.- K. Lee. Paratype . ASIZCR-000411, same data as holotype. Diagnosis. Vulcanolepas with small sized peduncular scales, ~ 0.43 mm length, protruding 0.3 mm from peduncle. First tooth of mandible large, sharp. Anterior and posterior rami of cirrus I with length ratio of rami bearing antenniform segments to robust segments ~1:1. Description (based on holotype , except capitulum and cirrus I include paratype for comparison). Hermaphrodite capitulum higher than wide; capitular height:width ratio 1.3:1 ( Figure 3 ). Capitulum with eight approximate plates; inter-spaces occupied by thin, cuticular membrane ( Figure 3 A–C). Carinal umbo apical, carina slightly bowed, surface with 16 horizontal growth lines; carinal height ~2/3 capitular height ( Figure 3D ). Tergum quadrangular, single ridge extending from basal angle to apex (apex angle 86 o ); surface with V-shaped growth lines; basal angle of tergum (60 o ), slightly elevated from capitular-peduncular edge, ~1/4 total height of capitulum ( Figure 3 ). Scutum quadrangular, umbo apical, basal angle 55 o , located at capitular-peduncular edge ( Figure 3 ), surface with 12 growth ridges. Medial latus equilateral triangular; umbo apical, apical angle 32.6 o ; surface with 20 straight horizontal growth lines. Rostrum triangular, with 14 horizontal growth lines ( Figure 3E ). Paratype with similar capitular morphology to holotype ( Figure 6A ). Inner surfaces of capitular plates white, smooth ( Figure 3F ). Peduncle: Peduncular-capitular ratio ~2:1 ( Figure 3A ). Peduncle with 32 scales/whorl just below capitular region, 28 scales/whorl at mid region of peduncle; scale width 0.43 mm (averaged from 3 scales), scales projecting 0.5 mm (averaged from 3 scales) from peduncle; scales rounded, smaller at capitular region of peduncle, larger at basal region. Cirri: All six pairs of cirri located close to each other. Cirrus I with anterior and posterior rami similar length (26 and 28 segments, respectively); proximal segments of both rami robust (cf Buckeridge et al. 2013 ), distal half of rami antenniform ( Figure 4A ); anterior and posterior rami with length ratio of ramus bearing antenniform segments to robust segments ~1:1 ( Figure 4A ). Paratype with ~1:1 length ratio of antenniform to robust segments along rami of cirrus I ( Figure 6B ); setae long, serrulate on both rami ( Figure 5A, B ). Cirrus II with both rami similar length (anterior 42, posterior 41 segments); last 10 proximal segments robust, segment height 1.5 times width ( Figure 4B ); rami antenniform from half to distal region; length ratio of antenniform segments to robust segments ~1: 1 in both rami ( Figure 4B ); antenniform segments of cirrus II with 3 pairs of long setae and 2 pairs of short setae ( Figure 4B ). Cirrus III with rami similar in length (both 54 segmented); setae serrulate, with very short, sparse setules ( Figure 4C ). Cirri IV–VI similar in morphology, both rami similar in length; shape of segments similar through whole length of rami ( Figure 4 D–F); intermediate segments of cirri IV–VI bearing 7 pairs of long setae ( Figure 4 D–F). FIGURE 3. Ƒulcanolepas fijiensis sp. nov. Holotype. A. Whole view, habitus, left side. B, C. Capitulum (left and right sides), showing paired terga (T) and scuta (S) and unpaired carina (CA), lateral (L) and rostrum (R). D, E. Capitulum, carinal and rostral view. F. Dissected capitulum, showing inner surface of capitular plates (white and smooth). Cirrus I is not separated from the remaining pairs of cirri (I, II, III indicate cirri I, II and III). Penis without basi-dorsal point, ~½ length of cirrus VI ( Figures 4G , 6C ). Caudal appendages unsegmented, minute ( Figures 4H , 6C ). Trophi: Maxilla subtriangular, exterior margin with simple setae ( Figure 5E, F ). Maxillule cutting edge slightly curved, with dense, simple setae on cutting margin; interior margin slightly convex ( Figure 5G, H ). Mandible tridentoid ( Figure 7A ); first tooth large, robust, sharp, separated from lower teeth ( Figure 7B ); second and third teeth comb-shaped, ~12 sharp spines on cutting edges ( Figure 7C, D ), cutting edges of second and third teeth short, ~1/5 total length of mandible; inferior angle blunt, with dense, sharp spines ( Figure 7E ); lower margin with simple setae ( Figure 7F ). Mandibular palp subtriangular, tip and outer margin with simple setae ( Figure 7G ). Labrum non bullate, with small, concaved notch; single array of small, sharp teeth at notch ( Figure 7H ). Etymology. The name denotes the discovery of this barnacle in the North Fiji Basin. Distribution. Presently only recorded in the North Fiji Basin.