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

Abstract

Abnormal embryonic development may result from mutations caused by genetics, environmental conditions or viruses. This study reports cases of cyclopia and a mouth malformation in two embryonic blue shark Prionace glauca collected off southern Brazil (South-western Atlantic). Such malformations are likely to reduce the chances of survival of embryos and neonates.

A mouthless late‐term coach whipray Himantura uarnak embryo (Elasmobranchii, Dasyatidae) has implications for our understanding of matrotrophy in chondrichthyans

“…Various teratological conditions have been reported in chondrichthyans, including bicephaly (Bornatowski & Abilhoa, 2009; Galván‐Magaña et al, 2011; Guida et al, 2013; Muñoz‐Osorio et al, 2013; Prado et al, 2020), cyclopia (Cabanillas‐Torpoco et al, 2023), anophthalmia (Ehemann et al, 2022; Rolim et al, 2020), albinism (Clark, 2002; Sandoval‐CaStillo et al, 2006), and assorted skeletal deformities (Bonfil, 1989; Moore, 2015; Wosnick et al, 2019; Zaera & Johnsen, 2011). Malfusion of the pectoral fins and head is one of the more commonly reported teratological conditions in the batoid elasmobranchs (Batoidea) (Ehemann et al, 2022), and the rostral malformation observed here is similar to occurrences in Rogers' round ray Urotrygon rogersi (Jordan & Starks 1895) (Mejía‐Falla et al, 2011) and Kuhl's maskray Neotrygon kuhlii (Müller & Henle 1841) (Ranjith et al, 2019).…”