Reproductive biology and population structure of the banded wrasse, Notolabrus fucicola (Labridae) around Kaikoura, New Zealand

Abstract

Notolabrus fucicola Richardson, a large common labrid inhabiting rocky reefs around New Zealand and southern Australia, were collected monthly from December 1996 to February 1998 around Kaikoura, New Zealand. They were found to be asynchronous spawners and followed the typical labrid spring-summer seasonal pattern of reproduction from July to December. Compared with other New Zealand labrids that are protogynous hermaphrodites, N. fucicola was found to be a secondary gonochorist, where individuals change sex before maturation. It is a dichromatic species but not sexually dimorphic. It is also monandric where only one morphological male type is present. Despite finding no transitional gonads, it is still possible that particular environmental or social conditions could induce sex change in at least a small proportion of fishes.