Lernanthropus tylosuri Richiardi, in Goggio, 1906

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 : 78-79

Lernanthropus tylosuri Richiardi, in Goggio, 1906

( Fig. 10C )

Syn: Lernanthropus cornutus Kirtisinghe, 1937

Material examined: none

Differential diagnosis: Cephalothorax longer than wide with linear lateral margins tapering towards straight anterior margin, bearing large process at each posterolateral corners ( Fig. 10C ). Trunk 2 to 3 times longer than 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 margin. Urosome comprising fifth pedigerous somite, genital complex and abdomen, all fused. Paired caudal rami short and wide; all caudal setae located in distal half of ramus. Parabasal flagellum long and slightly curved, reaching to middle of subapical segment of antennule. Leg 3 located ventrolaterally at rear of third pedigerous somite, forming long fleshy lamella, shoehorn-shaped, directed ventrally: third legs separate along midline. Leg 4 bilobate; inner and outer lobes flattened and entirely concealed beneath dorsal trunk plate; both lobes with complex apical ornamentation. Leg 5 absent. Body length of ♀ 7.8 mm, of ♂ 1.7 mm (length data from Pillai, 1985).

Distribution: The original description of L. tylosuri was based on material collected in the Mediterranean Sea by Richiardi (see Goggio, 1906). Cressey & Collette (1970) reported this species from numerous localities across the North and South Atlantic, North and South Pacific, and Indian Oceans. Their global survey included the first Australian record of L. tylosuri , from Strongylura incisa caught on the Great Barrier Reef (Queensland). Raja et al. (2018) reported a prevalence rate of 41.7% on Tylosurus crocodilus crocodilus (Peron & Lesueur, 1821) caught off S. E. India.

Remarks. This species has a confused nomenclatural history. The name Lernanthropus tylosuri was first used by Richiardi (1880) who simply listed the name in his Catalogo sistematico dei Crostacei che vivono sul corpo degli animali, as occurring on the gills of Tylosurus imperialis (Rafinesque) (as Thylosurus imperialis ). Richiardi’s name is a nomen nudum because citing a host together with a new name but in the absence of any description or illustration is not sufficient to constitute an indication according to the Code. Both Carus (1885) and Brian (1906) noted that L. tylosuri of Richiardi (1880) was a nomen nudum. However, Goggio (1906: Tav II, Fig. 10 ) provided an illustration of an adult female labelled as L. tylosuri and stated “[of Lernanthropus tylosuri I have not found any specimen and therefore I limit myself to reproducing a figure of Prof. S. Richiardi]”. The use of the binomial name and an illustration prior to 1931 is sufficient to constitute an indication under the Code. Wilson (1922) had presumably seen Goggio’s work because he was able to use the presence of the conspicuous paired posterolateral processes on the cephalothorax as a distinguishing character of L. tylosuri in his key to species.

Kirtisinghe (1937) established L. cornutus as a new species, but this is clearly the same species as the L. tylosuri of Wilson (1922) and Cressey & Collette (1970). Both names have subsequently been used by numerous researchers (see summary in Ho & Do, 1985). Cressey & Collette (1970) used L. tylosuri for this taxon in their major geographic survey and Pillai (1985) used it in his monograph on Indian parasitic copepods, but Ho & Do (1985) used L. cornutus in their important analysis of the phylogenetic relationships between the lernanthropid genera and cited numerous other users. Liu et al. (2009a) and Ho et al. (2011) continued to use L. cornutus . Given that Goggio (1906) attributes L. tylosuri to Richiardi and uses a figure provided by Richiardi to support the use of the name, we consider that the valid name and authority for this species is Lernanthropus tylosuri Richiardi, in Goggio, 1906 , and that Lernanthropus cornutus Kirtisinghe, 1937 is a subjective junior synonym.

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.