Philometra nemipteri Luo, 2001

Dewi, Kartika & Palm, Harry W., 2017, Philometrid nematodes (Philometridae) of marine teleosts from Balinese waters, Indonesia, including the description of Philometra damriyasai sp. nov., Zootaxa 4341 (4), pp. 577-584 : 580-581

Philometra nemipteri Luo, 2001

Host: Nemipterus japonicus (Bloch, 1791) ( Perciformes : Nemipteridae ).

Site of infection: Gonad.

Locality: South Bali Sea, Indonesia.

Date of collection: 23 July 2013.

Prevalence: 1 infected/17 examined.

Specimens deposited: Museum Zoologicum Bogoriense, Indonesia (MZBNa 725).

Remarks. Several specimens of P. nemipteri were reported from the gonads of one Nemipterus japonicus . Philometra nemipteri was originally described from Nemipterus virgatus (Houttuyn, 1782) from the Taiwan Strait based on a single female by Luo in 2001 ( Quiazon et al. 2008a), then recollected and redescribed from the same host in Japan by Quiazon et al. (2008a). This is the first record of this parasite from Indonesia, extending its range of distribution to the tropical Pacific.

The original description of P. nemipteri was inadequate ( Moravec 2006; Quiazon et al. 2008a), so we compared our specimens with Quiazon et al. (2008a) who provided a detailed description combined with molecular data. According to these authors, this species can be recognized by having a round shaped mouth, a highly swollen anterior esophagus forming a distinct bulb, and protruding lobular structures at the anterior tip in each of three esophaeal lobes. We identified these characters in our specimens and our female specimens have a morphology similar to that of P. nemipteri , especially the total body length (70.85–85.60 mm vs. 23.00–85.00 in Quiazon et al. 2008a), body width (0.57–0.70 mm vs. 0.28–0.74), number of cephalic papillae, shape of the mouth, total length and structure of the esophagus (0.76–0.88 vs. 0.655–1.025). These characters corresponded, to those in the original description from Quiazon et al. (2008a). As mentioned above philometrids exhibit a relatively high degree of host specificity and individual species are characterized by their site inside the host, particularly that of the gravid females. We recorded our specimens from a different species but belonging to the same genus Nemipterus , suggesting that the host specificity in this species is not that strict. This is a new host record of P. nemipteri in N. japonicus , and the first reported philometrid nematode in N. japonicus . It is also the second philometrid nematode from the gonads of fish in Indonesia, since Philometra cf. lateolabracis was reported from the gonads of Epinephelus ongus (Bloch, 1790) by Neubert et al. (2016).

In Nemipterus japonicus , we also recorded specimens from the eye cavity and the body cavity ( Table 1). The real identity of these worms remains unclear (this fish has not been known yet as a host of philometrids - Moravec, personal comunication).