Kyne & Simpfendorfer.. - Shark Specialist Group

aborting near-term embryos, with has been observed in this species (Ebert 1986). The
reproductive cycle has been postulated to be least one year (Capapé et al. 2004), but the
precise duration of gestation is unknown, although it is likely to be extended.
Ebert (1986) attempted to use traditional ageing methodologies on vertebral centra to age H.
griseus, but these were unsuccessful. McFarlane et al. (2002) examined the suitability of
using the neural arches to age this species and noted their potential given observed distinct
and regular bands, the number of which increased with total length. However, the authors
emphasized that their work was preliminary and that further research needs to include
validation of their method, in order to determine if bands are laid down annually. Compagno
(in prep. a) notes that the species is probably long-lived.
During a study of the reproductive biology of H. perlo off Kyushu, Japan (Tanaka and Mizue
1977), 218 females were observed, of which only a single gravid female with 11 embryos was
found. The embryos measured an average of 242mm TL and were considered to be near-term.
Bigelow and Schroeder (1948) reported litter sizes of 9–20 from Cuba (including L. Howell-
Rivero, pers. comm. in Bigelow and Schroeder 1948). Tanaka and Mizue (1977) indicate that
the species has no defined reproductive cycle off Japan. Females mature at 950–1050mm TL
off Japan (Tanaka and Mizue 1977), while a 932mm TL female from Cuba was also mature
(Bigelow and Schroeder 1948). With a maximum size of 1390mm TL (a record of 2140mm
TL may be erroneous) (Bigelow and Schroeder 1948, Compagno et al. 2005), female maturity
is reached from 67%TL max .
Hexanchus nakamurai is a very poorly-known species that is reportedly born at 400–430mm
TL; females mature at ~1420mm TL; males mature at ~1230mm TL (Springer and Waller
1969, Compagno in prep. a). A litter size of 13 has been reported for the species (Compagno
in prep. a).
Order Squaliformes. Dogfish Sharks.
Squaloid species are yolk-sac viviparous, the majority being lecithotrophic, while a few have
been shown to have limited matrotrophic input (limited histotrophs) (Musick and Ellis 2005).
Guallart and Vicent (2001) confirmed the gulper shark Centrophorus granulosus as strictly
lecithotrophic.
Family Echinorhinidae. Bramble Sharks.
Echinorhinid sharks are poorly-known and data on their biology is available only from
incidental observations. Bramble shark Echinorhinus brucus are born at 400–500mm TL with
maturity at 2000–2200mm TL for females and, although uncertain, 2540mm TL and