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Soriguer, Milagrosa C.; Vallespin, C.; Gómez-Cama, Carmen; Hernando, J. A.

doi:10.1023/a:1026529720060

Cited by 16 publications

(3 citation statements)

References 10 publications

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“…The diploid-polyploid ratio of Cobitis from Lake Müggelsee (Germany), however, at 1 : 7.4, is considered extreme, sex ratio 1 : 22 in favour of females (Bohlen and Ritterbusch 2000). According to Kotusz et al (2014), the diploid-polyploid ratio in Cobitis population has remained relatively stable for around a decade, though the male-female ratio varies with age in the majority of populations (Soriguer et al 2000, Patimar et al 2011, Mousavi Sabet et al 2011, 2012, Kırankaya and Ekmekçi 2014. As such, the survival rate differs between the sexes (Aoyama 2007, Juchno and Boroń 2010) and between individuals of different ploidies (Bobyrev et al 2003).…”

Section: Discussionmentioning

confidence: 99%

Growth differences in different biotypes of the hybrid complex of Cobitis elongatoides × Cobitis tanaitica (Actinopterygii: Cypriniformes: Cobitidae) in the Okna River (Danube River basin), Slovakia

Fedorčák

Koščo

Halačka

et al. 2017

Acta Ichthyol. Piscat.

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Fedorčák J., Koščo J., Halačka K., Manko P. 2017. Growth differences in different biotypes of the hybrid complex of Cobitis elongatoides × Cobitis tanaitica (Actinopterygii: Cypriniformes: Cobitidae) in the Okna River (Danube River basin), Slovakia. Acta Ichthyol. Piscat. 47 (2): 125-132.Background. Many of Cobitis subpopulations exist as diploid-polyploid hybrid complexes where polyploid gynogenetic females act as "sperm parasites" of diploid individuals. In addition to sexual strategy, the life history of such individuals is also affected by their growth performance. In order to elucidate unknown aspects of the Cobitis hybrid complexes we decided to identify differences in the annual size increments between individuals representing different ploidy and sex, and to compare the condition factor expressed by length-weight (L-W) relation within the same ploidy and sex groups. Material and methods. In total, 158 specimens representing Cobitis elongatoides (Băcescu et Mayer, 1969) ×Cobitis tanaitica (Băcescu et Mayer, 1969) hybrid complex were caught in August and September 2014, of which 132 were analysed. The fish were caught in the Okna River (Danube River basin), Slovakia. Sex was determined based on externally visible morphological features or based on microscopic observation of the gonads. Ploidy level was determined by means of flow cytometry on fin clips taken from each specimen. Age was estimated based on the total number of annuli visible on vertebrae. All statistical models were performed in the R statistical environment. Results. Sex ratio varied within age classes, with 3+ fish primarily composed of females and, 4+ fish mostly triploid. Maximum back-calculated lengths for diploid females were obtained up to 3+, and for the 4+ age group for triploid. L-W relations for adult males and females also differed significantly, but did not vary between diploid and triploid females. There were differences in at specific body lengths for Cobitis with different ploidy level. Diploid males were characterised by short annual age and length increments during the first two years of life. Annual increments in diploid females were highest overall though their frequency decreased after the reaching the fourth year of life (3+). On the contrary, annual increments in triploid females were the lowest within all groups until their fourth year, thought their frequency in the oldest age group (4+). Conclusion. In our study, we first confirmed that yearly increments and maximal age of Cobitis individuals are affected by different ploidy. Contrary, the L-W relations of gutted diploid and triploid females did not differ and they were affected only by sex. We suggest that the intensity of growth is more affected by ploidy, while the L-W of Cobitis is determined by intensity of feeding and stage of gonad development at the local conditions during season. Therefore, in the future studies of Cobitis growth and condition parameters the ploidy level of individuals should also be considered.

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Section: Discussionmentioning

confidence: 99%

Growth differences in different biotypes of the hybrid complex of Cobitis elongatoides × Cobitis tanaitica (Actinopterygii: Cypriniformes: Cobitidae) in the Okna River (Danube River basin), Slovakia

Fedorčák

Koščo

Halačka

et al. 2017

Acta Ichthyol. Piscat.

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“…The study species are two Iberian endemic freshwater fish: the arched-mouth nase, Iberochondrostoma lusitanicum (Collares-Pereira, 1980), a Critically Endangered fish from SW Portugal [ 35 ] with a maximum length of about 15 cm [ 36 ]; and the southern Iberian spined loach, Cobitis paludica (de Buen, 1930), a Vulnerable species distributed in southern and Eastern Iberia [ 37 ], reaching up to 13 cm [ 38 ]. Sampling occurred during the summer of 2018, in the streams of Barcarena and Jamor (Oeiras municipality, Portugal), where both species are present and Ranavirus infection has been previously confirmed (Coutinho & Rosa, unpublished).…”

Section: Methodsmentioning

confidence: 99%

Non-Lethal Detection of Ranavirus in Fish

Coutinho

Ford

Trafford

et al. 2023

Viruses

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Emergent infectious diseases have an increasing impact on both farmed animals and wildlife. The ability to screen for pathogens is critical for understanding host–pathogen dynamics and informing better management. Ranavirus is a pathogen of concern, associated with disease outbreaks worldwide, affecting a broad range of fish, amphibian, and reptile hosts, but research has been limited. The traditional screening of internal tissues, such as the liver, has been regarded as the most effective for detecting and quantifying Ranavirus. However, such methodology imposes several limitations from ethical and conservation standpoints. Non-lethal sampling methods of viral detection were explored by comparing the efficacy of both buccal swabbing and fin clipping. The study was conducted on two Iberian, threatened freshwater fish (Iberochondrostoma lusitanicum and Cobitis paludica), and all samples were screened using qPCR. While for C. paludica both methods were reliable in detecting Ranavirus, on I. lusitanicum, there was a significantly higher detection rate in buccal swabs than in fin tissue. This study, therefore, reports that fin clipping may yield false Ranavirus negatives when in small-bodied freshwater fish. Overall, buccal swabbing is found to be good as an alternative to more invasive procedures, which is of extreme relevance, particularly when dealing with a threatened species.

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“…Most of the still scarce studies on loach have mainly addressed aspects, such as its geographical distribution, genetic characterization, taxonomy and phylogeny (Doadrio et al 1988;Madeira et al 1992;Vasil'eva et al 1992;Perdices et al 1995Perdices et al , 2016Perdices 1997, 2005;Perdices and Doadrio 2001;Ludwig et al 2001), or some aspects of its biology, such as growth, feeding and reproduction (Lobón-Cerviá and Zabala 1984;Rodríguez-Jiménez 1987;Przybylski 1996, 2003;Przybylski and Valladolid 2000;Soriguer et al 2000;Oliva-Paterna et al 2002;Sánchez-Carmona et al 2008). Unfortunately, while habitat degradation and destruction are considered within the main factors causing the decline of loach populations, very few studies have investigated the habitat requirements and the ecology of the species.…”

Section: Introductionmentioning

confidence: 99%

Seasonal patterns of microhabitat selection in the Southern Iberian spined-loach Cobitis paludica

et al. 2022

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The Southern Iberian spined-loach Cobitis paludica is an Iberian endemism threatened by human activities, including habitat destruction. For this reason, the development of conservation and the recovery plans for the species calls for a precise knowledge of its habitat requirements. Here, microhabitat use and selection patterns were investigated to determine the limiting factors for the species in different seasons, corresponding to a gradient in flow conditions. The microhabitat of the loach was analysed in the River Jarama (Tagus River basin, central Spain) in the period of maximum activity between March and September 2013. No significant differences in microhabitat use were found between males and females, and only very weak ontogenetic changes were detected. The microhabitat used by the loach varied significantly throughout the study period, generally adapting to the flow-mediated dynamics of available habitat. The most stable pattern throughout the year was the use of very low water velocities. Additionally, the loach made selective use of certain microhabitat features, with slight adjustments to the seasonally changing habitat conditions. The loach significantly selected positions with abundant silt substrate and aquatic vegetation, and avoided coarser substrates. The availability of fine substrates and abundant vegetation is therefore a critical habitat requirement for the loach, which needs instream structures that provide foraging substrate, refuge and safe positions for spawning. Selection of refuge elements (deep habitats, aquatic vegetation) was especially apparent under low-flow conditions. Human activities leading to the loss of these critical microhabitats may threaten the survival of already scarce loach populations.

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Untitled

Cited by 16 publications

References 10 publications

Growth differences in different biotypes of the hybrid complex of Cobitis elongatoides × Cobitis tanaitica (Actinopterygii: Cypriniformes: Cobitidae) in the Okna River (Danube River basin), Slovakia

Growth differences in different biotypes of the hybrid complex of Cobitis elongatoides × Cobitis tanaitica (Actinopterygii: Cypriniformes: Cobitidae) in the Okna River (Danube River basin), Slovakia

Non-Lethal Detection of Ranavirus in Fish

Seasonal patterns of microhabitat selection in the Southern Iberian spined-loach Cobitis paludica

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