Lernanthropus belones Krøyer, 1863

Boxshall, Geoff A., Bernot, James P., Barton, Diane P., Diggles, Ben K., Q-Y, Russell, Atkinson-Coyle, Toby & Hutson, Kate S., 2020, Parasitic copepods of the family Lernanthropidae Kabata, 1979 (Copepoda: Siphonostomatoida) from Australian fishes, with descriptions of seven new species, Zootaxa 4736 (1), pp. 1-103 : 27

Lernanthropus belones Krøyer, 1863

( Fig. 10A )

Syn: Lernanthropus chlamydotus Wilson, 1922

Material examined: none.

Differential diagnosis: Cephalothorax longer than wide with linear lateral margins ( Fig. 10A ), widest posteriorly and tapering towards straight anterior margin. Trunk just over twice as long as cephalothorax; anterior part (second and third pedigerous somites) as wide as cephalothorax, with weakly convex margins; posterior part (fourth pedigerous somite) covered by long, cloak-like dorsal trunk plate, flared out laterally and widest towards posterior ( Fig. 10A ). Urosome comprising fused genital complex and abdomen bearing paired caudal rami. Caudal rami short and broad, with bluntly pointed apex; all caudal setae located in distal half of ramus. Leg 3 located ventrolaterally at rear of third pedigerous somite, forming shoehorn-shaped fleshy lamella, directed ventrally; third legs separate along midline. Leg 4 biramous; rami forming elongate, flattened lobes, entirely concealed beneath dorsal trunk plate in adult. Leg 5 absent. Mean body length of ♀ 2.85 mm, of ♂ 1.53 mm (from Cressey & Collette, 1970).

Distribution: In their monographic survey of copepods parasitic on needlefishes ( Belonidae ), Cressey & Collette (1970) reported L. belones from nine different host species collected at numerous localities in tropical, subtropical and warm temperate waters around the world. Their survey included a record of L. belones from Strongylura incisa caught off Arnhem Land (New Territory).

Remarks: Cressey & Collette (1970) recognized only two species of Lernanthropus on belonid hosts, L. belones and L. tylosuri Richiardi, in Goggio, 1906 (as L. tylosuri Richiardi, 1880 ). They distinguished between them solely on the basis of the shape of the cephalothorax: in L. tylosuri there are prominent posterolateral processes on the margin of the cephalothorax while L. belones lacks such processes. The males of both species were figured in detail by Cressey & Collette (1970), who noted fine scale differences in the shape of the lamellate leg 4, which they considered to be more deeply bifid at its apex in L. tylosuri than in L. belones .

Without discussion, Cressey & Collette (1970) placed L. chlamydotus Wilson, 1922 (as L. chlamydotes ) in the synonymy of L. belones and this synonymy was accepted by Ho & Do (1985). However, as recognized by Shiino (1955), the Japanese material reported by Yamaguti (1939) under the name L. chlamydotus is referable to L. tylosuri , as previously noted by Ho & Do (1985).

Figures

FIGURE 10. Lernanthropus belones Krøyer, 1863, adult ♀. A, habitus, dorsal. Lernanthropus brevicornutus Kabata, 1979 adult ♀. B, habitus, dorsal. Lernanthropus tylosuri Richiardi, in Goggio, 1906, adult ♀. C, habitus, dorsal. [Figures modified from Cressey & Collette, 1970, Kabata, 1979a, and Ho & Do, 1985, respectively]. Lernanthropus brevicornutus Kabata, 1979, adult ♀, D. urosome and caudal rami, dorsal; E, leg 4; F, tip of exopod of leg 4; G, tip of endopod of leg 4. Adult ♂. H, habitus, dorsal. All scale bars 0.5 mm.