habitat_narrative
Marine
Pterogymnus laniarius is found predominantly on deep, low, and high profile reefs and to a lesser extent over mud and sand down to 120 m (Fischer and Bianchi 1984, Smith and Heemstra 1986, Booth and Buxton 1997a). In the Southern Cape, this species was absent on sandy substrates shallower than 50 m (Wallace et al. 1984). Pterogymnus laniarius feeds on benthic invertebrates, predominately crabs with polychaetes, ophiuroids and fishes to a lesser extent while juveniles feed primarily on mysids (Hecht 1976). Clarke and Buxton (1984) showed this species is a benthic invertebrate feeder, prey associated with both hard and soft substrates were present in the diet although the latter were more important. The mouth structure is shown to be well adapted to feeding over soft substrates. Pterogymnus laniarius can reach 16 years of age, has a maximum recorded length of 40.5 cm FL, and the maximum recorded weight is 1.5 kg (Booth and Buxton 1997a).Reproduction
Pterogymnus laniarius is a late gonochorist (sensu rudimentary hermaphrodite) that spawns throughout the year (Booth and Buxton 1997a) peaking from September to May (Hecht and Baird 1977). Spawning occurs primarily on the Agulhas Bank (Booth and Buxton 1997a). This species attains 50% sexual maturity between four to five years of age (Hecht and Baird 1977, Booth and Buxton 1997a, Booth and Hecht 1998). Lengths at 50% maturity were found to be of 28.6 cm TL for combined sexes in the Southeastern Cape during the 1970s (Hecht and Baird 1977, Booth and Hecht 1998) but had declined to 20.4 cm FL for combined sexes in the 1990s (Booth and Buxton 1997a, Booth and Hecht 1998).
Generation length for P. laniarius is estimated to be eight years, using the following equation for a gonochoristic fish species: Generation length = Σxlxmx/Σlxmx
