On four species of echinorhynchid acanthocephalans from marine fish in Halong Bay, Vietnam, including the description of three new species and a key to the species of Gorgorhynchus

Abstract

Four species of echinorhynchid acanthocephalans were collected from marine fish off Cat Ba Island, Halong Bay, Gulf of Tonkin, Vietnam, in the spring of 2009. Acanthocephalus halongensis n. sp. (Echinorhynchidae) from the redtail scad, Decapterus kurroides Bleeker 1855 (Carangidae), has a unique proboscis armature with a spiniform basal hook with lateral root and an incomplete receptacle wall posteriorly. Gorgorhynchus tonkinensis n. sp. (Rhadinorhynchidae) also from D. kurroides, has long, slender, winding lemnisci, many epidermal nuclei, and a narrow anterior trunk with a shoulder armed with 20 circles of tightly packed spines, the posterior four circles of which have abruptly larger spines than those in the anterior circles. Neorhadinorhynchus atypicalis n. sp. (Cavisomidae) from the rabbitfish, Siganus fuscescens (Houttuyn 1782) (Siganidae), has the largest number of proboscis hooks per row, testes wider than long, and four clustered cement glands. Micracanthorhynchica kuwaitensis Amin and Sey 1996 (Rhadinorhynchidae) from the spottail needlefish Strongylura strongylura (van Hasselt 1823) (Belonidae) was similar to specimens originally described from the Arabian Gulf off the Kuwaiti coast. These acanthocephalans were collected in small numbers but stood out as uniquely and considerably different from their closest relatives to warrant their reporting. All species of acanthocephalans and their host and geographic distribution are described, and a key to the species of Gorgorhynchus is provided.

Morphological and molecular description of Rhadinorhynchus laterospinosus Amin, Heckmann & Ha, 2011 (Acanthocephala, Rhadinorhynchidae) from marine fish off the Pacific coast of Vietnam

“…Of these, six new species of Neoechinorhynchus Stiles & Hassall 1905, one new species of Heterosentis Van Cleave, 1931, and two new species of Rhadinorhynchus Lühe 1911 were described [8, 14, 15]. Four other species of Echinorhynchid acanthocephalans from marine fishes in Halong Bay were described [4] and five other new species from fishes and amphibians of eight collected host species were also described. Three other species of Rhadinorhynchus and one species of Gorgorhynchus were otherwise previously reported from marine fishes in Vietnam by other observers [19].…”

Redescription and molecular analysis of Neoechinorhynchus (Neoechinorhynchus) johnii Yamaguti, 1939 (Acanthocephala, Neoechinorhynchidae) from the Pacific Ocean off Vietnam

“…Of these, six new species of Neoechinorhynchus Stiles & Hassall 1905, one new species of Heterosentis Van Cleave, 1931, and two new species of Rhadinorhynchus Lühe 1911 were described [9, 15, 16]. Four other species of Echinorhynchid acanthocephalans from marine fishes in Halong Bay were also described [6], and five other new species from fishes and amphibians of eight collected host species were described [18]. Three other species of Rhadinorhynchus and one species of Gorgorhynchus were otherwise previously reported from marine fishes in Vietnam [20].…”

Acanthocephalans from fishes and amphibians in Vietnam, with descriptions of five new species

“…A number of acanthocephalan species from freshwater fishes and other vertebrates were previously described in Vietnam by Amin and Ha [ 3 , 4 ] and Amin et al . [ 6 , 9 – 11 , 32 ].…”

“…Eleven species of acanthocephalans were collected from marine fishes off the eastern seaboard of Vietnam at Halong Bay in 2008 and 2009. Of these, 6 new species belonging to Neoechinorhynchus Stiles and Hassall, 1905, one new species of Heterosentis Van Cleave, 1931, and three new species of Acanthocephalus Koelrouther, 1771, Gorgorhynchus Chandler, 1934, and Neorhadinorhynchus Yamaguti, 1939 were recently described by Amin and Ha [ 4 ]. Two new species of Rhadinorhynchus Lühe, 1911 were described from marine fishes in the same bay [ 7 ].…”