Bowmouth Guitarfish - Biology and Ecology

Biology and Ecology

The bowmouth guitarfish is an active species with a shark-like swimming style. It is most active at night, and is not known to be territorial. This species has crushing dentition and feeds mainly on bottom-dwelling crustaceans, such as crabs and shrimp, though molluscs and bony fishes are also consumed. The bowmouth guitarfish is known to fall prey to the tiger shark (Galeocerdo cuvier). The thorns on its head and back are employed in defense (including butting). Parasites that have been documented from this species include the tapeworm Tylocephalum carnpanulatum, the trematode Melogonimus rhodanometra, the monogeneans Branchotenthes robinoverstreeti and Monocotyle ancylostomae, and the copepod Nesippus vespa. There is a record of an individual being serviced by bluestreak cleaner wrasses (Labroides dimidiatus). This species is aplacental viviparous, with the developing embryos being sustained by yolk. Michael (1993) reported the litter size as 4 and the birth size as 45 cm (18 in), while Last and Stevens (2009) noted a female specimen pregnant with 9 mid-term embryos, measuring 27–31 cm (11–12 in) long. Males attain sexual maturity at 1.5–1.8 m (4.9–5.9 ft) long.