Лейкоцитарная формула широколобой нототении
            
              Notothenia coriiceps
            
            на протяжении годового цикла

Abstract A number of variable descriptive accounts of Aspersentis megarhynchus (von Linstow, 1892) Golvan, 1960 have been reported from specimens collected from many species of fish in various locations off Antarctic islands. We have described a new population from Notothenia coriiceps Richardson (Nototheniidae) off Galindez Island, West Antarctica, and features not previously reported, resolved the taxonomic controversies and nomenclature, and emended and updated the generic diagnosis taking into account the newly observed structures. These are depicted in microscopic images and include the outer spiral wall of the proboscis receptacle, the thicker dorsal wall of the receptacle compared to the ventral wall, parts of the female reproductive system, the separate cement gland ducts, the dorsal position of the male gonopore and more detail of proboscis hooks and trunk spines. It is surprising that the newly observed features were missed from the many descriptions of A. megarhynchus created since the original description. The variability in A. megarhynchus is noted with a comparison of the morphometrics of our specimens vs. those in six other descriptions. We also analysed the metal composition of hooks and spines using energy-dispersive X-ray analysis and concluded a molecular characterization of the species based on 18S DNA gene, with related phylogenetic analyses.

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Fine structure of the retinal pigment epithelium and cones of Antarctic fish Notohenia coriiceps Richardson in light and dark-conditions

Revista Brasileira de Zoologia ◽

10.1590/s0101-81752007000100004 ◽

2007 ◽

Vol 24 (1) ◽

pp. 33-40 ◽

Cited By ~ 5

Author(s):

Lucélia Donatti ◽

Edith Fanta

Keyword(s):

Epithelial Cells ◽

Pigment Epithelium ◽

Retinal Pigment ◽

Antarctic Fish ◽

Basal Region ◽

Dense Cytoplasm ◽

Transmission Electron ◽

Notothenia Coriiceps ◽

The Antarctic ◽

Pigment Epithelial Cells

The Antarctic fish Notothenia coriiceps Richardson, 1844 lives in an environment of daily and annual photic variation and retina cells have to adjust morphologically to environmental luminosity. After seven day dark or seven day light acclimation of two groups of fish, retinas were extracted and processed for light and transmission electron microscopy. In seven day dark adapted, retina pigment epithelium melanin granules were aggregated at the basal region of cells, and macrophages were seen adjacent to the apical microvilli, between the photoreceptors. In seven day light adapted epithelium, melanin granules were inside the apical microvilli of epithelial cells and macrophages were absent. The supranuclear region of cones adapted to seven day light had less electron dense cytoplasm, and an endoplasmic reticulum with broad tubules. The mitochondria in the internal segment of cones adapted to seven day light were larger, and less electron dense. The differences in the morphology of cones and pigment epithelial cells indicate that N. coriiceps has retinal structural adjustments presumably optimizing vision in different light conditions.

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An amended description of two Gyrodactylus species (Platyhelminthes: Monogenea) parasitizing Antarctic Notothenioid fish

Journal of Helminthology ◽

10.1017/s0022149x18001098 ◽

2018 ◽

Vol 94 ◽

Cited By ~ 1

Author(s):

I. Heglasová ◽

V. Nezhybová ◽

I. Přikrylová

Keyword(s):

Internal Transcribed Spacer ◽

Host Record ◽

Sister Group ◽

Weddell Sea ◽

Locality Record ◽

New Host ◽

New Host Record ◽

Notothenia Coriiceps ◽

Species Groups ◽

The Antarctic

Abstract Species identification based on the morphometry of opisthaptoral hard parts, in combination with internal transcribed spacer ribosomal DNA (ITS rDNA) region sequences, confirmed the presence of four viviparous Gyrodactylus von Nordman, 1832 (Plathyhelminthes, Monogenea) species on Nototheniid fish from the Prince Gustav Channel (Weddell Sea, Antarctica). Gyrodactylus antarcticus Gusev, 1967 was found mostly on Trematomus newnesi Boulenger (93 specimens) but also on T. bernacchii Boulenger (one specimen), the latter representing a new host record for this species. Gyrodactylus byrdi Hargis & Dillon, 1968 and G. coriicepsi Rokicka, Lumme & Ziętara, 2009 were recorded on their type hosts, T. newnesi and Notothenia coriiceps Richardson, respectively. Gyrodactylus wilkesi Hargis & Dillon, 1968 was found mostly on the fins of T. bernacchii (29 specimens), but also on T. hansoni Boulenger (one specimen) and T. newnesi (three specimens). The finding of G. wilkesi on T. newnesi represents a new host record. The low number of Gyrodactylus specimens may indicate an accidental infection. The occurence of all four Gyrodactylus species in the Prince Gustav Channel represents a new locality record. According to phylogentic methods, the newly redescribed monogeneans belong to the Antarctic lineage, forming a sister group to North American and European marine Gyrodactylus species, and consist of two species groups, one comprising G. coriicepsi and G. nudifronsi Rokicka, Lumme & Ziętara, 2009, and the other G. anarcticus and G. wilkesi.

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