Anuretes branchialis Rangnekar, 1953

Boxshall, Geoff, 2018, The sea lice (Copepoda: Caligidae) of Moreton Bay (Queensland, Australia), with descriptions of thirteen new species, Zootaxa 4398 (1), pp. 1-172 : 24-26

Anuretes branchialis Rangnekar, 1953

( Fig. 8 )

Syn: Henicophilus japonicus Yamaguti & Yamasu, 1959 Material examined. 14♀♀ from Platax teira (Forsskål, 1775) (TC16981), 11 January 2016; 7♀♀ QM Reg. No. W53046; 7♀♀ NHMUK Reg. Nos. 2017.183–189.

Site on host. attached near distal tips of gill filaments.

Differential diagnosis. Cephalothorax dorsoventrally flattened with well-developed marginal membranes; elongate, about 1.6 times longer than wide, and somewhat rectangular in outline; thoracic zone extending posteriorly completely concealing fourth pedigerous somite and anterior part of genital complex in dorsal view ( Fig. 8A ). Frontal plates lacking lunules. Genital complex quadrangular, about 1.2 times wider than long; abdomen reduced and fused to genital complex. Antenna with posteriorly-directed spinous process on proximal segment ( Fig. 8B ). Post-antennal process vestigial; associated papillae uni- or bisensillate. Maxillary whip lacking. Sternal furca with straight, slightly divergent, pointed tines ( Fig. 8C ). Distal exopodal segment of leg 1 with 3 plumose setae on posterior margin; spine 1 short, distal spines 2 and 3 each with accessory process; seta 4 just longer than spine 1. Leg 3 with 2-segmented exopod ( Fig. 8D ); proximal segment bearing large curved spine and lacking inner seta, compound distal segment with 4 naked spines plus 3 plumose setae; endopod 2-segmented ( Fig. 8E ), first segment unarmed, distal segment with 2 terminal setae. Leg 4 uniramous, 3-segmented ( Fig. 8F ); exopodal segments 1 and 2 armed with I and III spines, respectively. Mean body length of adult female 2.47 mm, range 2.34 to 2.55 mm (based on 10 specimens).

Remarks. The complex taxonomic history of A. branchialis was summarised by Dojiri & Ho (2013) who provided an up-to-date synonymy and a detailed redescription of the female. The male is still unknown, more than half a century after discovery of the female. The distinctive features of A. branchialis include: the extensive thoracic zone of the dorsal cephalothoracic shield which completely conceals the fourth pedigerous somite and extends over the anterior half of the genital complex, combined with the presence of a sternal furca, lack of maxillary whip, and the 2-segmented endopod in leg 3, armed with 0-0; 2 setae.

This species has been reported from the gills of six host species representing five different families (Dojiri & Ho, 2013: Table VII). It has a wide geographical range in the Indo-Pacific, having been reported from the Arabian Sea, India, Sri Lanka, Indonesia, Taiwan, Japan, the Philippines and Australia (see Dojiri & Ho, 2013). It was previously reported from Platax teira captured in Moreton Bay by Kabata (1965a), under the name Henicophilus japonicus .

Figures

FIGURE 8. Anuretes branchialis Rangnekar, 1953, female. A, habitus, dorsal; B, antenna, vestigial post-antennal process, maxilluleand post-oral process, drawn in situ; C, sternal furca; D, exopod of leg 3; E, endopod of leg 3; F, leg 4. Scale bars:1.0 mm on A, 100 µm on B, C, F, 50 µm on D, E.