Structure, diversity and evolutionary patterns of expressed MHC class IIB genes in chub (Squalius cephalus), a cyprinid fish species from Europe

AbstractThe egg release–mating comparison, heterospecific matings and mating success under two hybridization conditions – (i) mixing one sex per species and (ii) mixing both sexes from each species – were investigated to determine whether silver bream Blicca bjoerkna and common bream Abramis brama can hybridize in nature.The results revealed that non-matings in hybridization experiments of silver bream females × common bream males can be explained by territorial and aggressiveness activities observed in common bream. In common bream females × silver bream males, heterospecific matings were observed but their numbers were significantly lower than the spawning numbers, and in this experiment, a female mated with one to four heterospecific males. In mixing both sexes from both species, similar spawning – mating numbers were observed but heterospecific matings accounted for only 27% of the total matings, with 24% accounting for heterospecific matings between common bream females and silver bream males, directly or by opportunism. Mating success was characterized by the occurrence of fertilized eggs after matings.Natural hybridization occurred preferentially between common bream females and silver bream males.

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MHC genes and oxidative stress in sticklebacks: an immuno-ecological approach

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2005.3450 ◽

2006 ◽

Vol 273 (1592) ◽

pp. 1407-1414 ◽

Cited By ~ 55

Author(s):

Joachim Kurtz ◽

K. Mathias Wegner ◽

Martin Kalbe ◽

Thorsten B.H Reusch ◽

Helmut Schaschl ◽

...

Keyword(s):

Oxidative Stress ◽

Susceptibility To Infection ◽

Mhc Genes ◽

Histocompatibility Complex ◽

Individual Host ◽

Experimental Approaches ◽

Mhc Class Iib ◽

Class Iib ◽

First Time ◽

And Oxidative Stress

Individual variation in the susceptibility to infection may result from the varying ability of hosts to specifically recognize different parasite strains. Alternatively, there could be individual host differences in fitness costs of immune defence. Although, these two explanations are not mutually exclusive, they have so far been treated in separate experimental approaches. To analyse potential relationships, we studied body condition and oxidative stress, which may reflect costs of immunity, in three-spined sticklebacks that had been experimentally exposed to three species of naturally occurring parasite. These sticklebacks differed in a trait, which is crucial to specific parasite defence, i.e. individual genetic diversity at major histocompatibility complex (MHC) class IIB loci. Oxidative stress was quantified as tissue acrolein, a technique that has been applied to questions of immuno-ecology for the first time. We measured gene expression at the MHC and other estimates of immune activation. We found that fish with high levels of MHC expression had poor condition and elevated oxidative stress. These results indicate that MHC-based specific immunity is connected with oxidative stress. They could, thus, also be relevant in the broader context of the evolution of sexually selected signals that are based on carotenoids and are, thus supposed to reflect oxidative stress resistance.

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The fishes of the Bolaman Stream, Northern Turkey

AQUATIC RESEARCH ◽

10.3153/ar21004 ◽

2021 ◽

Vol 4 (1) ◽

pp. 38-54

Author(s):

Serkan Saygun

Keyword(s):

Black Sea ◽

Fish Species ◽

Fish Fauna ◽

The Black Sea ◽

Fish Samples ◽

First Time ◽

Squalius Cephalus

In this study, the fish species inhabiting the Bolaman Stream drains to the Black Sea from the Fatsa coast (Ordu Province, Turkey) was reported for the first time. The study was caught out non-periodically by sampling from seven stations in the Bolaman Stream between July 2017 and November 2018. Fish samples were captured with an electroshock device. With this study, it was determined that the fish fauna of the Bolaman Stream is represented by 10 species in five families (Acheilognothidae, Cyprinidae, Gobiidae, Leuciscidae, and Salmonidae). These species were as follows, respectively Rhodeus amarus, Barbus tauricus, Capoeta banarescui, Neogobius fluviatilis, Ponticola turani, Alburnus derjugini, Squalius cephalus, Vimba vimba, Alburnoides fasciatus, and Salmo coruhensis.

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