Genetic and historical evidence of common sawsharks Pristiophorus cirratus in the waters of southern Queensland

Abstract

In 2011, a male pristiophorid was caught by a prawn trawler north east of Cape Moreton, Queensland, Australia. Molecular analyses confirmed the specimen to be the common sawshark Pristiophorus cirratus. Historical catch data indicate the occurrence of the species in the region but this is the first verified record of P. cirratus occurring in the waters of southern Queensland. Together, these records extend the recognised northern limit of P. cirratus by c. 500 km, which suggests that further investigation of its distribution is warranted.

The Sawshark Redemption: Current knowledge and future directions for sawsharks (Pristiophoridae)

“…Additionally, environmental DNA (eDNA) methods could be applied to examine species distributions. Improving our knowledge in this area would be beneficial, particularly in light of recently uncovered extensions to the latitudinal ranges (Nevatte et al., 2019; Weigmann et al., 2014) and depth ranges (Raoult et al, 2020) for some species.…”

“…It is unclear whether these differences in denticle morphology relate to habitat or lifestyle but could be explored further in future taxonomic studies on sawsharks. (Naylor, Caira, Jensen, Rosana, Straube, et al, 2012;Naylor, Caira, Jensen, Rosana, White, et al, 2012;Nevatte, Wueringer, Gillings, & Williamson, 2019). Monophyly of the genus was restored, however, in the study by Naylor, Caira, Jensen, Rosana, Straube, et al (2012) when each codon of the ND2 sequence was examined separately.…”

“…warreni and P. nancyae), but distributions of sawsharks are often poorly known and require further investigation. Indeed, range extensions for two species have been reported in recent years (Nevatte et al, 2019;Weigmann et al, 2014).…”

“…warreni —modified from Fowler (2004); Pristiophorus cirratus —modified from Walker (2016a) to include range extension reported by Nevatte et al. (2019); P. delicatus —modified from Rigby and Heupel (2015) to include specimens from Yearsley et al. (2008) and Rigby et al.…”

“…Often phylogenetic studies that incorporate sawsharks are examining broad‐scale relationships among elasmobranch groups and have thus far only included up to three sawshark species as representatives of the pristiophorids. However, a few studies have indicated that P. japonicus clusters with Warren's sixgill sawshark ( Pliotrema warreni , Pristiophoridae) rather than with other members of its genus such as P. cirratus and P. nudipinnis , thereby rendering the genus Pristiophorus non‐monophyletic (Naylor, Caira, Jensen, Rosana, Straube, et al, 2012; Naylor, Caira, Jensen, Rosana, White, et al, 2012; Nevatte, Wueringer, Gillings, & Williamson, 2019). Monophyly of the genus was restored, however, in the study by Naylor, Caira, Jensen, Rosana, Straube, et al (2012) when each codon of the ND2 sequence was examined separately.…”