Lecithostaphylus tylosuri sp. nov. (Digenea, Zoogonidae) from the digestive tract of the needlefish Tylosurus acus imperialis (Teleostei, Belonidae)

Abstract

Lecithostaphylus tylosuri sp. nov. (Digenea, Zoogonidae) specimen were collected from the digestive tract of Tylosurus acus imperialis (Teleostei, Belonidae) caught off the eastern coast of Tunisia. L. tylosuri is very similar to its closest relatives, L. retroflexus and L. nitens. It can be easily distinguished from L. retroflexus (Molin, 1859) in having a more extensive vitellarium, with follicles reaching from the posterior margin of the acetabulum and extending beyond the posterior margin of the testes and a coiled seminal vesicle. L. tylosuri differs from L. nitens as illustrated by Linton 1898, in having a longer cirrus pouch (0.7 mm vs 0.36 mm, respectively) overlapping the anterior edge of the ventral sucker and a submarginal genital pore (submedian in L. nitens). It's also different from L. nitens as described by Manter 1947 in the vitelline disposition and in having the greater sucker ratio (1 : 1.3-2.1 vs 1 : 1.3-1.6, respectively). Members of the genus Lecithostaphylus are cosmopolitan, frequently reported from beloniform fishes (Exocoetidae and Belonidae) (Brooks 1990), and recently mentioned in damselfishes (Pomacentridae) (Cribb et al. 1992, Toman 1992. In this work, we describe a new species of Lecithostaphylus from the digestive tract of the needlefish T. a. imperialis. This belonid is a marine epipelagic subspecies of Tylosurus acus (Lacépède, 1803) essentially restricted to the Mediterranean Sea. This new digenean species is described, characterised below, and its host specificity is discussed. In addition, the im-*Corresponding author: lassad.neifar@fss.rnu.tn Unauthenticated Download Date | 5/9/18 5:57 AM Lecithostaphylus tylosuri sp. nov. 51 pact of the host's sex and size on infection parameters, such as prevalence and abundance, were also examined.

Parasitic infections in the Mediterranean needlefish Tylosurus acus imperialis (Teleostei: Belonidae) off Tunisian coast

“…Raibaut [6][7][8]. However, the quantitative aspect of parasites of T. acus imperialis has not previously been studied.…”