Multiple morphological abnormalities in a blue shark Prionace glauca (Linnaeus, 1758) embryo from the Peruvian coast, southeast Pacific

Abstract

This study reports for the first time a case of multiple morphological abnormalities in a blue shark Prionace glauca embryo collected on the Peruvian coast, southeast Pacific. External exploration and radiograph picture showed duplicated parts in the cephalic region (mouths and eye sockets) and trunk anomalies (thoracic lordosis and rolled caudal fin). The duplicate face parts in a single head seen in the embryo, suggest a diprosopia anomaly.

Teratological records in blue shark Prionace glauca embryos from the South-western Atlantic Ocean

“…However, similar reports in the South Atlantic Ocean are less frequent in comparison with the North Atlantic Ocean. In both the Atlantic and Pacific Oceans, the most commonly reported malformations for this species at this stage of development are diprosopia (usually two heads) and twisted vertebral columns (Mancini et al ., 2006; Bejarano-Álvarez et al ., 2011; Galván-Magaña et al ., 2011; Hevia-Hormazábal et al ., 2011; Ehemann et al ., 2016; Lamarca et al ., 2017; Pastén-Marambio et al ., 2018; Rodriguez-Romero et al ., 2019; Ramírez-Amaro et al ., 2019; Kanagusuku et al ., 2020). In this study, we report the second embryo with a kind of cyclopia for the South-western Atlantic Ocean (Ferreira et al ., 2002).…”

“…Furthermore, trunk abnormalities (e.g. spinal anomalies, Parenzan, 1979; Lamarca et al ., 2017; Kanagasuku et al ., 2020) and albinism (Escobar-Sanchéz et al ., 2014; Becerril-García et al ., 2017) have also been reported.…”

Morphological abnormalities in the Chilean Eagle ray Myliobatis chilensis (Myliobatiformes: Myliobatidae) off the Peruvian coast, Southeast Pacific

“…Reports of morphological anomalies in elasmobranchs throughout the Eastern Paci昀椀c are scarce and most are relatively recent (Clark, 2002;Escobar-Sánchez et al, 2014) (Table 2). Speci昀椀cally, in Peru there is only one report of an abnormality in a Prionace glauca embryo (Kanagusuku et al, 2020). Likewise, worldwide records of anomalies in the genus Myliobatis are limited to only three cases: (i) albinism (De Jesus-Roldan, 1990), (ii) cephalic anomalies (Ramírez-Amaro et al, 2013) in Myliobatis californica, and (iii) hermaphroditism in M. aquila (Rafra昀椀-Nouria et al, 2017).…”

Morphological abnormalities in seven American round ray specimens: A review of America's batomorph anomalies

“…The biological characteristics of several species of this family are unknown; however, biannual to triannual reproductive periodicity has been mentioned for some species of Urotrygon , with adult females having litters of up to six pups (Acevedo et al., 2015; Mejía‐Falla et al., 2012; Santander‐Neto et al., 2016). These particular aspects may result in a higher probability of producing specimens with morphological abnormalities, which has been hypothesized to be one of the primary explanations for the blue shark having the highest abnormality occurrence among shark species worldwide (Ehemann et al., 2016; Galván‐Magaña et al., 2011; Kanagusuku et al., 2020; Mancini et al., 2006).…”

“…However, the aetiology of cojoined twinning is still uncertain (Sans‐Coma et al., 2017). Over 24 shark specimens with this anomaly have been recorded worldwide (Ehemann et al., 2016; Kanagusuku et al., 2020; Lamarca et al., 2017; Prado et al., 2020; Sans‐Coma et al., 2017), with Prionace glauca being the most frequent species. In contrast, at least three batomorph cases with this anomaly are available, two for Rhinoptera spp.…”