Metaverruca defayeae Buckeridge, 1994

Chan, Benny K. K., Prabowo, Romanus Edy & Lee, Kwen-Shen, 2010, North West Pacific deep-sea barnacles (Cirripedia, Thoracica) collected by the TAIWAN expeditions, with descriptions of two new species, Zootaxa 2405, pp. 1-47 : 31-35

Metaverruca defayeae Buckeridge, 1994

Figures 2 F, 23, 24

Metaverruca defayeae Buckeridge, 1994: 109 , fig. 9. — Buckeridge, 1997: 138.

Material examined. CEL-BB-100, 4 specimens, Stn. CP371 (24º28.521’N, 122º12.821’E, 26 Aug. 2006, depth: 582–613 m), BD 10.22–13.10 mm.

Diagnosis. External shell smooth, with dense growth lines; movable tergum and scutum with 4 articular ribs; mandible with 5 teeth; caudal appendage short, <length of basal segment of pedicle of cirrus VI.

Description. Shell white, low conic, sides steep, surface smooth, with dense growth lines; basis membranous ( Fig. 2 F); operculum sub-parallel to basis ( Fig. 2 F); orifice D-shaped ( Fig. 2 F); rostrum and carina articulated with up to 5 ribs ( Fig. 2 F); fixed scutum with myophore; movable tergum quadrangular, strong apical basal rib and secondary 3 ribs interlocking with movable scutum; movable scutum triangular, articulating with movable tergum by 3 secondary ribs and 1 apico-basal rib. Maxilla bilobed, with dense setae ( Fig. 23 A); maxillule notched, 2 large, cuspidate setae above notch, 6 cuspidate setae in notch,> 10 cuspidate setae below notch on expanded margin ( Fig. 23 B); mandible with 4 main teeth, 2 small teeth representing fifth ( Figs 23 C, G, E), lower margin hirsute, sharp spines and pectinations at inferior angle ( Fig. 23 E); mandibular palps elongated, setae along superior margin ( Fig. 23 D); labrum concave, with row of fine, small teeth ( Figs 23 F, H). Cirrus I with rami unequal, outer ramus 21-segmented, inner ramus 12-segmented ( Fig. 24 A); cirrus II with outer ramus longer, 19-segmented, inner ramus shorter, 13-segmented ( Fig. 24 B); cirri III–VI similar; cirrus III with outer ramus 23-segmented, inner ramus 22-segmented; cirrus IV with outer ramus 27- segmented, inner ramus 28-segmented; cirrus VI with outer ramus 32-segmented, inner ramus 28-segmented ( Fig. 24 C, D, E); caudal appendages short, 8-segmented, length <height of basal segment of pedicel of cirrus VI ( Fig. 24 F).

Remarks. This is a new record for Taiwanese waters. Buckeridge (1994) concluded Metaverruca defayaea to be morphologically close to M. recta ( Aurivillius, 1898) . The major difference between these two species is the number of interlocking ribs on the movable scutum and tergum; M. defayaea has 4 whilst M. recta has 3. In the present study, the fifth tooth of the mandible of M. defayaea is represented by 2 small teeth, whilst the fifth of M. defayaea in Buckeridge (1994) is represented by a single small tooth. The taxonomic status of M. defayaea in Taiwanese waters will need to be further evaluated from larger samples sizes and with support from a molecular approach.

Figures

FIGURE 2. Taiwanese deep-sea barnacles (right side view on A – C, top view for D – I). A. Annandaleum japonicum biramosum, B. Litoscalpellum spinosus sp. nov., C. Scalpellum stearnsii, D. Altiverruca longimandible sp. nov., E. Altiverruca navicula, F. Metaverruca defayeae, G. Metaverruca recta, H. Rostratoverruca krugeri, I. Hexelasma velutinum.

FIGURE 23. Metaverruca defayeae. A. Maxilla, B. Maxillule, C. Mandible, D. Mandibular palp, E. Lower margin of mandible, F. Labrum, G. First and second teeth of mandible, H. Cutting edge of mandible, showing fine teeth. Scale bars in µm.

FIGURE 24. Metaverruca defayeae. A. Cirrus I, B. Cirrus II, C. Cirrus III, D. Cirrus IV, E. Cirrus VI, showing caudal appendage, F. Caudal appendage. Scale bars in mm.