Morphological deformities in the pelvic fin and clasper in specimens ofPotamotrygon marquesi(Chondrichthyes: Myliobatiformes: Potamotrygoninae)

Abstract

We report deformities in the pelvic fin and clasper skeleton in specimens of Potamotrygon marquesi from Acre, Northwestern Brazil. The malformations involve skeletal deformities in the pelvic girdle, right clasper skeleton, and severe muscular and skeletal deformities in the left or right pelvic fin and clasper, including the loss of all of its terminal components. Descriptions of malformations dealing with elasmobranchs are extensive in the literature and are important for future studies dealing with their probable causes. Nevertheless, although the reasons of these deformities are herein possibly linked to malformation (as a result of stress or chemical contaminants) or predation, the anomalies in the muscular and skeletal components of the pelvic fin and clasper are described in detail and compared to a non‐deformed specimen.

First record of pughead deformity in Myrichthys ocellatus (Ophichthidae) and Ephinephelus marginatus (Epinephelidae)

“…Deformities in the fish body have been commonly reported for both actinopterygians and elasmobranchs under the most varied forms (Dawson, 1964(Dawson, , 1966(Dawson, , 1971Dawson & Heal, 1976;Moore, 2015;Silva & Casas, 2020). These morphological abnormalities have either genetic or epigenetic origin due to adverse environmental conditions that persist during early stages of ontogenetic development (Dahlberg, 1970;Slooff, 1982).…”

Nothing in excess is good: Double pelvic fin malformation in the wild‐caught hill stream loach,Indoreonectes evezardi(Day, 1872) from biodiversity hotspot of India

“…In addition, loaches, including I. evezardi , are known to migrate upstream during their breeding season (Keskar et al., 2014; Shaji, 2011), which consequently raises the risk for exposure of their embryonic stages to riverine contaminants, making them more likely to be targets for pollutant‐induced malformation (Jezierska et al., 2009). Despite the possible cause of the deformities discussed herein, the possibility of developing a malformed phenotype due to a spontaneous/random mutation of the gene (such as Hox gene) or regulatory sequence of locus involved in the morphogenesis of pelvic fins cannot be overlooked (Capretz Batista da Silva & da Silva Casas, 2020; Heupel et al., 1999; Mazurais et al., 2009; Tanaka et al., 2005; Van Eeden et al., 1996). However, further gene‐specific in‐depth molecular investigations are required before a conclusion can be made.…”

Primeiro registro de eversão vaginal em Psammobatis rutrum Jordan, 1891 (Rajiformes: Arhynchobatidae)

“…: Sandoval-Castillo, Mariano-Melendez & Villavicencio-Garayzar, 2006;Bottaro, Ferrando, Gallus, Girosi & Vacchi, 2008;Jones, Hoffmayer & Gropp, 2016;Quigley, Carlos, Barros-Garcia & MacGbahann, 2018;Lara-Mendoza & Guerra-Jiménez, 2020), morfológicas (Ex. : El Kamel-Moutalibi, Mnasri, Boumaïza, Reynaud & Capapé, 2011Pastén-Marambio, Hevia-Hormazábal, Acuña & Vega, 2018;Marouani, Jarray, Karaa & Jarboui, 2019;Ranjith, et al, 2019;Mulas et al, 2020;Rolim, Rotundo, Stabile & Vaske-Júnior, 2020) e reprodutivas (Oddone & Amorim, 2008;Ribeiro-Prado, Oddone, Amorim & Capapé, 2009;Capapé, El Kamel-Moutalibi, Mnasri, Boumaïza & Reynaud, 2012;Costa, Borges & Capapé, 2013 & Capapé, 2017;Zhao, Chen, Jiang, Yang, & Xiao, 2017;Ehemann & González-González, 2018;Burgos, Gonzalez, Falla, & Escalon, 2019;Capapé, Kassar, Reynaud, & Hemida, 2019;Sen, Dash, Valappil, Kizhakudan, & Chakraborty, 2020;Silva & Silva-Casas, 2020). Grande parte das anomalias relacionadas aos órgãos reprodutivos está relacionada a intersexualização, deformidades ou ausência de cláspers.…”