Trypanosoma pacifica sp. n. from the English sole Parophrys vetulus Girard from Oregon

Trypanosoma epinepheli n. sp. (Kinetoplastida) from a farmed marine fish in China, the brown-marbled grouper (Epinephelus fuscoguttatus)

An outbreak of trypanosomosis occurred in farmed Epinephelus fuscoguttatus in Xincun Bay, province of Hainan, South China Sea. The infected fish showed loss of appetite, lethargy, emaciation, severe anemia, and splenomegaly. Light and scanning electron microscopic examination of bloodstream trypomastigotes revealed morphological features typical for small-sized marine fish trypanosomes. The trypanosome possesses a short body length (mean 22.3 μm, range 17.6-25.9 μm) and narrow body width (mean1.7 μm, range 1.3-2.0 μm), a central nucleus, a narrow but distinct undulating membrane, and a relatively long free flagellum (mean 10.1 μm, range 7.4-13.3 μm). The kinetoplast is situated at approximately one quarter of body length from posterior extremity. The division process of this trypanosome was observed in the peripheral blood of the host, and occurred by transverse constriction at a point between the kinetoplasts. Comparison of the small subunit rDNA (SSU rDNA) sequences revealed that the trypanosome from E. fuscoguttatus showed 93.4-97.1% identity with the available sequences from Trypanosoma spp. from other piscine hosts. Phylogenetic analysis supported the existence of an aquatic clade, and the present trypanosome grouped with other marine fish trypanosomes, in a subclade together with Trypanosoma senegalense. Based on the differences in morphological characteristics, host species, and molecular data, the trypanosome infecting E. fuscoguttatus is considered to be a new species, for which we propose the name Trypanosoma epinepheli n. sp.

Trypanosomes infecting cod Gadus morhua L. in the North Atlantic: a resurrection of Trypanosoma pleuronectidium Robertson, 1906 and delimitation of T. murmanense Nikitin, 1927 (emend.), with a review of other trypanosomes from North Atlantic and Mediterranean teleosts

Trypanosomes were isolated from Atlantic cod Gadus morhua L. collected from several fjords in western Norway. Morphological studies showed that the 12 infections studied represented a single species, identified as Trypanosoma pleuronectidium Robertson, 1906 which is resurrected and redescribed. This species is characterised by its body length (57.9 +/- 5.4 microm), nearly central nucleus (NI = 1.05 +/- 0.12) and relatively short post-kinetoplastic (PK) region (3.2 +/- 0.8 microm). T. pleuronectidium is transmitted by the leech Calliobdella nodulifera (Malm). T. murmanense Nikitin, 1927 (emend.) is delimited to a species transmitted by the leech Johanssonia arctica (Johansson). This species is separated from T. pleuronectidium by its attained body length, more anterior nucleus, presence of cytoplasmic refractive granules, adnuclear vacuoles and by a longer PK region. Partial SSU rDNA sequences of T. pleuronectidium and T. murmanense from Norway (1980 nt) diverged by 1.9%. The nominal North Atlantic and Mediterranean trypanosome species are reviewed, and T. flesi Lebailly, 1904, T. bothi Lebailly, 1905 and T. limandae Brumpt & Lebailly, 1904 are considered synonyms of T. platessae Lebailly, 1904. T. triglae senegalensis Ranque, 1973 is not considered conspecific with T. triglae Neumann, 1909, and consequently raised to species status as T. senegalense Ranque, 1973. Some other likely synonymies are discussed. In addition to T. pleuronectidium and T. murmanense, the following marine teleost trypanosomes are provisionally listed as valid species pending further study: T. callionymi Brumpt & Lebailly, 1904; T. cotti Brumpt & Lebailly, 1904; T. delagei Brumpt & Lebailly, 1904; T. dorhni Yakimov, 1911; T. gobii Brumpt & Lebailly, 1904; T. laternae Lebailly, 1904; T. myoxocephali Fantham, Porter & Richardson, 1942; T. platessae Lebailly, 1904; T. scorpaenae Neumann, 1909; T. soleae Laveran & Mesnil, 1901; T. triglae Neumann, 1909; and T. yakimovi Yakimov, 1911.