Cirracanthus spinosus Dojiri & Cressey, 1987

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 : 38-40

Cirracanthus spinosus Dojiri & Cressey, 1987

( Fig. 3 )

Cirracanthus spinosus Dojiri & Cressey 1987: 157 ; Dojiri & Ho 1987: 42.

Material examined. 4 Ƥ, 2 3 and 2 copepodids ( WAM C38665–C38666, C38740), ex 2 Chaetodermis penicilligerus (Cuvier) ( WAM P.9098.001), Shark Bay, Western Australia, Australia, 21 September 1964; 20 Ƥ, 5 3 (1 damaged) and 3 copepodids ( WAM C38654, C38741–C38742), ex 1 C. penicilligerus ( WAM P.9132.001), Shark Bay, Western Australia, Australia, 8 October 1964; 138 Ƥ, 176 3 and 125 copepodids ( WAM C38631, C38663– C38664, C38743–C38746), ex 1 C. penicilligerus ( WAM P.31951.001), unknown locality, 31 May 1983; 1 Ƥ ( WAM C38651), ex C. penicilligerus ( WAM P.6257.001), Shark Bay, Western Australia, Australia, 1958; 81 Ƥ, 12 3 and 5 copepodids (AM P65253), ex 1 C. penicilligerus (AM I 20788-004), Carnarvon, Western Australia, Australia, May 1972; 8 Ƥ (AM P65254), ex 1 C. penicilligerus (AM I15557-275), Gulf of Carpentaria, Australia, 27 November 1963; 9 Ƥ (1 damaged) ( MAGNT Cr014944), ex 1 C. penicilligerus ( MAGNT S.12333-001), Ashmore Reef, Timor Sea, 29 September 1987; 11 Ƥ (2 damaged) ( MAGNT Cr014945), ex 1 C. penicilligerus ( MAGNT S.13272-002), Booby Island, Queensland, Australia, 29 November 1991; 3 Ƥ paratypes ( USNM 228421), ex C. penicilligerus ( USNM 176890), Great Barrier Reef, Queensland, Australia.

Supplemental description of adult female. Body 0.93 mm long (excluding caudal setae) and 0.31 mm wide (n = 4) ( Fig. 3 A). Caudal ramus ( Fig. 3 B) bearing 7 setae (seta I minute) and posterodorsal flap. Third endopodal segment of leg 4 ( Fig. 3 C) armed with 2 unequal spines and 1 intermediate spine.

Description of adult male. Body 0.57 mm long (excluding caudal setae) and 233 µm wide (n = 5) ( Fig. 3 D). Genital double-somite wider (88 µm) than long (69 µm). Abdomen 88 µm long and 61 µm wide, composed of 3 free somites. Caudal ramus longer (22 µm) than wide (16 µm), bearing similar elements as in female.

Maxilliped ( Fig. 3 E) 4-segmented; syncoxa with short, distomedial seta; basis elongate, armed with 2 proximal setae and 2 inner longitudinal rows of spinules (spinules on anterior surface shorter than on posterior surface); first endopodal segment short, unarmed; second endopodal segment elongate, bearing long seta on posterior surface, 2 short setae on anterior surface, short row of denticles at mid-point of concave margin and minute teeth at distal end. Middle spine on third endopodal segment of leg 3 ( Fig. 3 F) longer than adjacent spines. Outer margin of first 2 spines on third endopodal segment of leg 4 ( Fig. 3 G) serrate and distally tapered.

Attachment sites. Predominantly on gill filament lamellae; rarely on branchial cavity wall.

Remarks. This species was described by Dojiri & Cressey (1987) from Chaetodermis penicilligerus (Cuvier) (as Chaetoderma penicilligera ) captured from the Great Barrier Reef, Australia. This species is the only tetraodontiform-parasitising taeniacanthid known thus far that attaches almost exclusively to the gill filament lamellae of its host, with its body nestled between the gill filaments and its anterior end pointed toward the gill arch.

Comparisons between our material and three C. spinosus paratype females revealed that Dojiri & Cressey (1987) had overlooked seta I and the posterodorsal flap on the caudal rami, as well as incorrectly reported two spines and one seta on the third endopodal segment of leg 4 when in fact there are two spines and an intermediate spine. Cirracanthus spinosus may be readily distinguished from C. monacanthi by having an armature formula of II, I, 5 rather than II, I, 4 on the third exopodal segment of leg 3. For additional distinguishing characters, see “Remarks” section of C. monacanthi .

Figures

FIGURE 3. Cirracanthus spinosus Dojiri & Cressey, 1987, female (A – C) and male (D – G). (A) habitus, dorsal; (B) caudal ramus (seta I indicated by arrowhead), dorsal; (C) leg 4 endopod, anterior; (D) habitus, dorsal; (E) maxilliped, anterior; (F) leg 3 endopod, anterior; (G) leg 4 endopod, anterior. Scale bars: A = 0.20 mm; B = 12.5 µm; C, E – G = 25 µm; D = 0.10 mm.