Nesippus orientalis Heller, 1868

Dippenaar, Susan M. & Jordaan, Bea P., 2012, Notes on the morphology and ecology of the adult females of Nesippus species (Siphonostomatoida: Pandaridae) with a key for identification, Zootaxa 3170, pp. 18-30 : 19

Nesippus orientalis Heller, 1868

Distinguishing characteristics. Dorsal plates on 4th thoracic segment, no median sinus posteriorly on genital complex (see Dippenaar & Jordaan 2006, Fig. 1A), bifid maxilliped claw (see Dippenaar & Jordaan 2006, Fig. 3 C), leg 4 exopod with 5 spines and 4 pinnate setae and endopod with 4 pinnate setae (see Dippenaar & Jordaan 2006, Fig. 4 D).

Ecological aspects. Nesippus orientalis consists of two cryptic species ( Dippenaar et al. 2010) with the first infecting 9 different host species while the second infects three different host species (cryptic species of specimens collected from Mustelus mustelus (Linnaeus, 1758) is unknown) (Fig. 1). The first cryptic species exhibits prevalences of 70–100% on Carcharodon carcharias (Linnaeus, 1758) , Alopias vulpinus (Bonnaterre, 1788) and Sphyrna zygaena (Linnaeus, 1758) (Fig. 1) with a mean intensity of 189 and mean abundance of 178 individuals per C. carcharias host but with values of 50 and less for all the other host species (Fig. 1). In general, the prevalence, mean intensity and mean abundance is higher on the Lamniformes than on the Carcharhiniformes . The second cryptic species exhibits 100% prevalence and mean intensity and mean abundance of 40 individuals per host on Sphyrna mokarran (Rüppell, 1837) with much lower infection values on the other two host species (Fig. 1).

This is the first record of N. orientalis infecting M. mustelus.

FIGURE 1. The prevalence (%), mean intensity and mean abundance of Nesippus orientalis Heller, 1868 on its different host species (* indicates second cryptic species, # indicates unknown cryptic species).

Figures

FIGURE 3. Nesippus vespa Kirtisinghe, 1964, adult female. (A) Antennule; (B) Mandible; (C) Maxillule. Scale bars: A, 50 µm; B, 10 µm; C, 25 µm.

FIGURE 4. Nesippus crypturus Heller, 1868, adult female SEM micrographs. (A) Cephalothorax, ventral; (B) Antennule, first segment; (C) Maxilla, calamus; (D) Leg 2, exopod; (E) Leg 4; Line drawing of (F) Mandible. Scale bars: A, 200 µm; B, C, E,