scholarly journals Multiple male reproductive morphs in the invasive round goby (Apollonia melanostoma)

2009 ◽  
Vol 35 (2) ◽  
pp. 302-308 ◽  
Author(s):  
Julie R. Marentette ◽  
John L. Fitzpatrick ◽  
Robert G. Berger ◽  
Sigal Balshine
2009 ◽  
Vol 84 (1) ◽  
pp. 87-92 ◽  
Author(s):  
J.M. Mühlegger ◽  
F. Jirsa ◽  
R. Konecny ◽  
C. Frank

AbstractTwo invasive fish species, the round goby Apollonia melanostoma syn. Neogobius melanostomus (Pallas 1814) and the bighead goby Neogobius kessleri (Günther, 1861), have established a firm population in Austrian waters during the past 15 years. As there have been no records of the parasite fauna from these populations, a total of 79 specimens of A. melanostoma and 12 specimens of N. kessleri were examined for parasites between May and October 2007 from three different sampling sites from the Danube River in Austria. In total 12 parasite taxa were recovered. The protozoans Trichodina sp. and Ichthyophthirius multifiliis from the gills and skin; two crustacean species, Paraergasilus brevidigitus and Ergasilus sieboldi, from the gills; and the two monogeneans Gyrodactylus sp. and Dactylogyrus sp., from the skin and gills respectively, all occurred at low prevalence and intensities. Furthermore, cystacanths of the acanthocephalan Acanthocephalus lucii were found in the body cavity. Metacercariae of the digeneans Diplostomum sp. and Tylodelphys clavata were found in the lens of the eye and the vitreous humour, respectively. Adults of two digeneans, Nicolla skrjabini and Bunodera nodulosa, were found in the intestine. In addition, during this survey metacercariae of the Holarctic digenean Bucephalus polymorphus, encysted in the skin and fins, with prevalence up to 78%, were recorded for the first time in Austria.


2009 ◽  
Vol 35 (2) ◽  
pp. 266-271 ◽  
Author(s):  
Ana Carolina Taraborelli ◽  
Michael G. Fox ◽  
Ted Schaner ◽  
Timothy B. Johnson

2012 ◽  
Vol 48 (6) ◽  
pp. 81-85 ◽  
Author(s):  
A. A. Soldatov ◽  
Ye. V. Pashkova ◽  
T. A. Kukhareva
Keyword(s):  

2017 ◽  
Vol 26 (2) ◽  
pp. 392-405 ◽  
Author(s):  
O.A. Diripasko ◽  
T.A. Zabroda

A total of 38 morphometric characters of the round goby Neogobius melanostomus melanostomus (Pallas, 1814) were studied in its native range in the Sea of Azov. The aim was to assess joint effect of sexual dimorphism and size variability on overall variability within groups of samples (populations) using appropriate methods of traditional statistical analysis (one-dimensional and multivariate statistics). Sex and size-dependent variability was studied based on model samples of males and females of different size. Most of the studied morphometric characters of round goby from the Sea of Azov demonstrated statistically significant sex- and size-dependent in-group variability. The pattern of the variability suggests that, for a comparison of round goby from different sea regions and between populations, separate samples of males and females within the range 9–13 cm SL should be examined in order to minimise the effect of the size and sex factors. The approach of searching for the most informative size range could be useful not only for further studies of infraspecific variation but for comparisons between morphologically close gobiin species.


2014 ◽  
Vol 35 (2) ◽  
pp. 415-453 ◽  
Author(s):  
Magdalena Błażewicz-Paszkowycz ◽  
Robert M. Jennings ◽  
Karen Jeskulke ◽  
Saskia Brix

AbstractIn Tanaidacea morphological identification of male individuals to the species level is complicated by two factors: the presence of multiple male stages/instars confuse the assessment of sexual stage while strong sexual dimorphism within several families obscures the morphological affinities of undescribed males to described females. Males of Paratanaoidea are often morphologically quite different from females and have not been discovered for most genera so far, which has led to the assumption that some tanaidaceans might have parthenogenetic reproduction or simply have undeveloped secondary sex traits. As a part ofthe IceAGE project (Icelandic marine Animals: Genetics and Ecology), with the support of molecular methods, the first evidence for the existence of highly dimorphic (swimming) males in four families of the superfamily Paratanaoidea (Agathotanaidae, Cryptocopidae, Akanthophoreidae, and Typhlotanaidae) is presented. This study suggests that these males might be the next instars after juvenile or preparatory males, which are morphologically similar to females. It has been assumed that “juvenile” males with a restricted ability for swimming (e.g., undeveloped pleopods) have matured testes, are capable of reproduction, and mate with females nearby, while swimming males can mate with distant females. Our explanation of the dimorphism in Tanaidomorpha lies in the fact that males of some species (e.g.,Nototanais) retain the same lifestyle or niche as the females, so secondary traits improve their ability to guard females and successfully mate. Males of other species that have moved into a regime (niche) different than that of the female have acquired complex morphological changes (e.g.,Typhlotanais).


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