Taeniacanthus brayae, Tang, Danny, Uyeno, Daisuke & Nagasawa, Kazuya, 2011

Tang, Danny, Uyeno, Daisuke & Nagasawa, Kazuya, 2011, Parasitic copepods of the family Taeniacanthidae (Crustacea) from triggerfishes (Teleostei, Balistidae) and filefishes (Teleostei, Monacanthidae) collected in the Indo-West Pacific region, with descriptions of two new species of Taeniacanthus Sumpf, 1871, Zootaxa 3103, pp. 33-56 : 44-48

Taeniacanthus brayae n. sp.

( Figs 6–8 )

Type material. Ƥ holotype (AM P65291) and 4 Ƥ paratypes (AM P69674–P69676), ex 1 Pervagor melanocephalus (Bleeker) (AM I33744-020), Boot Reef, Coral Sea, 26 January 1993.

Other material examined. 1 Ƥ (AM P65108), ex P. melanocephalus (AM I20445-012), Christmas Island, Australia, 25 May 1978; 2 Ƥ ( WAM C38655), ex 1 P. melanocephalus ( WAM P.30629.008), Madang, Papua New Guinea, 6 February 1993; 1 Ƥ ( WAM C38763), ex P. melanocephalus ( WAM P.30406.013), Sibuan Island, Malaysia, 13 February 1992; 1 Ƥ ( WAM C38622), ex P. melanocephalus ( WAM P.29047.004), Ashmore Reef, Timor Sea, 14 September 1986; 1 Ƥ ( MAGNT Cr014961), ex P. melanocephalus ( MAGNT S.13676-062), Table Island Reef, Madang, Papua New Guinea, 14 October 1992.

Description of adult female. Body 471 µm long (excluding caudal setae) and 227 µm wide (n = 3) ( Fig. 6 A). Prosome composed of cephalothorax (first pedigerous somite combined with cephalosome) and 3 free pedigerous somites. Urosome short, comprised of 5th pedigerous somite, genital double-somite and 3 free abdominal somites; last prosomal somite completely overlapping fifth pedigerous somite and partially obscuring genital double-somite. Genital double-somite wider (80 µm) than long (40 µm). Abdomen 37 µm long and 48 µm wide; first 2 abdominal somites naked; anteroventral surface of anal somite ( Figure 6 B) with 3 interrupted, transverse rows of spinules. Caudal ramus ( Fig. 6 B) longer (16 µm) than wide (14 µm), bearing posterodorsal flap and 6 setae (seta I not observed); ventrolateral and outer and middle terminal setae bearing longitudinal row of minute spinules on outer margin; middle terminal seta longest, at least 3 times longer than outer terminal seta.

Rostral area ( Fig. 6 A, C) highly protuberant, lacking sclerotised structure on ventral surface. Antennule ( Fig. 6 D) 6-segmented (articulation between ancestral segments XIV–XVII and XVIII–XX not expressed); armature formula: 5, 15, 8, 4, 2 + 1 aesthetasc, and 7 + 1 aesthetasc. Antenna ( Fig. 6 E) indistinctly 4-segmented; coxobasis bearing usual distal seta; first endopodal segment with inner seta; second endopodal segment bearing 2 unequal pectinate processes (each process armed with seta and ornamented with row of minute spinules) and claw-like spine; third endopodal segment elongate, extending beyond pectinate processes and bearing 2 claw-like spines and 4 unequal setae (innermost seta broken). Postantennal process ( Fig. 6 F) with wide base and pointed tine.

Labrum ( Fig. 6 G) with spinules along posterior margin and crescentic row of spinules on ventromedian surface. Mandible ( Fig. 6 H) with terminal and subterminal blades, each spinulate along inner margin. Paragnath ( Fig. 7 A) unornamented. Maxillule ( Fig. 7 B) lobate, bearing 3 naked setae (2 setae broken in figure), spinulate seta and anterior knob-like process. Maxilla ( Fig. 7 C) 2-segmented; syncoxa unarmed; basis armed with spinulate terminal process and naked seta. Maxilliped ( Fig. 7 D–E) 3-segmented; syncoxa bearing small seta; basis armed with 2 proximal naked setae; terminal (endopod) segment a curved claw, bearing 2 naked basal setae (posterior seta minute), basal protrusion and transverse flanges at distal end.

Legs 1–4 biramous ( Figs 7 F–I, 8A–E), with 2-segmented rami on leg 1 and 3-segmented rami on legs 2–4. Armature on rami of legs 1–4 as follows (Roman numerals = spines; Arabic numerals = setae; int. = intermediate spine):

Leg 1 ( Fig. 7 F) coxa, basis and rami flattened and expanded. Intercoxal sclerite squat, armed posteriorly with small and large spinules. Coxa with lateral row of spinules; basis ornamented with rows of small spinules on ventral surface and row of large spinules on posterior border; posterior margin of leg 1 exopod bearing row of spinules. Leg 2 intercoxal sclerite ( Fig. 7 G) rectangular, with rows of spinules along posterior margin; coxa with spinules scattered on ventral surface and bordering posterolateral margin; basis with spinules along posterior and inner margins. Leg 2 exopodal spines ( Fig. 7 H) spinulate along outer margin and bearing terminal flagellum; usual row of spinules along outer margin of segments not observed. First 2 endopodal segments of leg 2 ( Fig. 7 I) ornamented with lateral row of setules and spinules; spines on third endopodal segment spinulate along lateral margin and bearing small distomedial tooth. Leg 3 intercoxal sclerite ( Fig. 8 A) wider than that of leg 2, with spinules along posterior margin. Leg 3 coxa, basis and exopod similar to those of leg 2, except inner margin of basis lacking spinules. Leg 3 endopodal segments and spines ( Fig. 8 B) ornamented as in leg 2, except innermost spine with 2 distal teeth rather than 1. Leg 4 intercoxal sclerite ( Fig. 8 C) 4 times wider than long; coxa and basis similar to those of leg 3. First 2 exopodal segments of leg 4 ( Fig. 8 D) with lateral row of spinules; all exopodal spines weakly sclerotised, attenuate; first spine bristled along outer margin; third exopodal segment with distal protrusion armed with 2 minute elements. First 2 endopodal segments of leg 4 ( Fig. 8 E) with row of spinules; first 2 spines spinulate along outer margin (second spine with several distomedial teeth); intermediate spine spinulate along inner margin. Leg 5 ( Fig.

8F–G) uniramous, 2-segmented. Protopodal segment armed with dorsolateral naked seta and row of spinules on lateral and posterior borders; free exopodal segment with patches of spinules along inner margin and armed with 1 subterminal and 3 terminal setae; row of spinules present at base of outer and inner terminal setae; middle terminal seta longest of 4 exopodal setae. Leg 6 ( Fig. 8 H) vestigial, represented by 3 unequal naked setae at egg sac attachment area.

Adult male. Unknown.

Attachment site. Orbit.

Etymology. This species is named in honour of Dianne Bray, Collection Manager (Ichthyology and Herpetology) at Museum Victoria.

Remarks. This is the second record of a copepod infecting Pervagor melanocephalus

(Bleeker). Taeniacanthus brayae n. sp. resembles the new species described immediately below. For the distinguishing features of T. brayae n. sp., see the ‘Remarks’ section of the following taxon.

Figures

FIGURE 6. Taeniacanthus brayae n. sp., female. (A) habitus, dorsal; (B) anal somite and caudal ramus, ventral; (C) rostral area, ventral; (D) antennule, ventral; (E) antenna, medial; (F) postantennal process, medial; (G) labrum, ventral; (H) mandible, anterior. Scale bars: A = 0.10 mm; B – C, F – H = 12.5 µm; D – E = 25 µm.

FIGURE 7. Taeniacanthus brayae n. sp., female. (A) paragnath, ventral; (B) maxillule, anterior; (C) maxilla, posterior; (D) maxilliped, medial; (E) distal end of maxilliped, posterior; (F) leg 1, anterior; (G) leg 2 intercoxal sclerite, coxa and basis, anterior; (H) leg 2 exopod, anterior; (I) leg 2 endopod, anterior. Scale bars: A – B, E = 6.25 µm; C – D, F – I = 12.5 µm.

FIGURE 8. Taeniacanthus brayae n. sp., female. (A) leg 3 intercoxal sclerite, anterior; (B) leg 3 endopod, anterior; (C) leg 4 intercoxal sclerite, anterior; (D) leg 4 exopod, anterior; (E) leg 4 endopod, anterior; (F) leg 5, lateral; (G) leg 5, medial; (H) leg 6, dorsal. Scale bars: A, C = 6.25 µm; B, D – H = 12.5 µm.