
TY  - JOUR
A1  - Francis, MP 
A1  - Francis, RICC 
T1  - Growth rate estimates for New Zealand Rig (<I>Mustelus lenticulatus</I>)
JF  - Marine and Freshwater Research
JO  - Mar. Freshwater Res.
Y1  - 1992
VL  - 43
IS  - 5
SP  - 1157
EP  - 1176
KW  - length-frequency analysis, tagging, age at maturity, MULTIFAN, GROTAG
UR  - https://doi.org/10.1071/MF9921157 
N2  - Growth rate estimates were obtained for New Zealand rig (Mustelus lenticulatus) by analysing length  frequency and tag-recapture data. Rig (0+) sampled by set-net in Porirua and Pauatahanui Inlets grew from about 25-30 cm total length at birth to 46-49 cm at age of about 6 months. Samples of juvenile and adult rig trawled in Pegasus Bay and Hauraki Gulf suffered from under-representation of large adults, probably because of escapement. Growth curves derived from length-frequency analysis indicated that Pegasus Bay males matured at 5.0 years and had a minimum longevity of 12 years. Hauraki Gulf males and females matured at 3.7 and 4.7 years, respectively. Growth rates and ages at maturity fell within the ranges reported for other Mustelus species. Tagging data for South Island rig suggested that females grew faster than males. However, growth rate estimates from length-frequency analysis were 2.7-3.3 times greater than estimates from tagging data, probably because the latter were biased by the combined effects of tagging on growth and set-net mesh selectivity. 
ER  -

