Reproductive biology of Urotrygon microphthalmum (Batoidea: Urotrygonidae) from north‐eastern Brazil, tropical west Atlantic Ocean

Abstract

The reproductive biology of Urotrygon microphthalmum was studied based on specimens caught as by-catch in shrimp (Litopenaeus schmitti, Xiphopenaeus kroyeri, Farfantepenaeus subtilis and Farfantepenaeus brasiliensis) fishing operations between March 2010 and March 2012 on the coast of Pernambuco, Brazil. Females reached a larger total length (LT ) and total body mass (MT ) (298 mm and 148 g) than males (250 mm and 90 g). Length at maturity was estimated to be 188 and 199 mm LT for males and females. Uterine fecundity ranged from one to four embryos (mean ± s.d.: 1·85 ± 0·45). Size at birth was estimated to be 105 mm LT . Gestation lasted between 4 and 5 months. The reproductive cycle of U. microphthalmum is hypothesized to be asynchronous and biannual.

Size at sexual maturity, seasonal variation by maturity stages, and fecundity of the spotted round ray (Urobatis maculatus) and the thorny stingray (Urotrygon rogersi) from the northern tropical eastern Pacific

“…In several round rays such as U. halleri , U. jamaicensis , the small‐eyed round stingray Urotrygon microphthalmum Delsman 194, U. chilensis , and even U. rogersi the female size seems to be related to the litter size or the size of the pups (Babel, 1967; Fahy et al, 2007; Mejía‐Falla et al, 2012; Rubio‐Lozano, 2009; Santander‐Neto et al, 2016; Serrano‐Acevedo, 2007). However, these relationships were not found for U. rogersi and U. maculatus in the present study.…”

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

“…These American endemic round ray species are small‐ to medium‐sized stingrays (170‐ to 714‐mm TL), constituting one of the most abundant Eastern Pacific by‐catch batomorph species of the local and industrial shrimp fisheries (Last et al., 2016; Mejía‐Falla et al., 2011, 2012; Torres‐Huerta et al., 2015). 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).…”

“…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).…”