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.

Niche partitioning in the Fiordland wrasse guild

“…Scarlet wrasse Pseudolabrus miles are similarly hermaphroditic but larger, reaching a size of ~32.5 cm in length and maturing at around 4 yr (Francis 1988). Banded wrasse Notolabrus fucicola are the largest of the 3 species (~40 cm) and are secondary gonochorists, reaching maturity at ~20 cm (Denny & Schiel 2002). Labrids are one of the most abundant and conspicuous reef fish families within New Zealand (Denny 2005) and have been observed to feed primarily on sea urchins Evechinus chloroticus, mollusks and crustaceans (Russell 1983, Jones 1984b, Denny & Schiel 2001.…”

“…Surface salinity was recorded at 2 m depth using replicate CTD surveys over 100 m intervals with a Seabird SBE 19 CTD during 1998, 2002(Wing et al 2004. Surface salinity values represent average salinity in the upper 2 m of the water column.…”

Could thermal sensitivity of mitochondria determine species distribution in a changing climate?

“…The family Labridae is a large group of wrasse species occupying reef habitats in both temperate and tropical waters (Cowman et al, 2009). Two species were investigated: the cold temperate Notolabrus fucicola (banded/purple wrasse) (J. Richardson 1840), which is most abundant in southern coastal waters of the South Island of New Zealand (winter and summer temperatures of 9 and 13°C, respectively) (Denny and Schiel, 2001;Denny and Schiel, 2002), and the tropical Thalassoma lunare (lunar wrasse) (Linneaus 1758), which inhabits Indo-Pacific waters including North-Eastern Australian reefs (winter and summer temperatures of 25 and 28°C, respectively) (Ackerman, 2004;Randall et al, 1990). We also compared data from these two species with published data from N. celidotus, which inhabits temperate reefs of the North Island of New Zealand (winter and summer temperatures of 15 and 21°C, respectively) (Ayling and Cox, 1982).…”

Fecundity of banded wrasse(Notolabrus fucicola)from Otago, Southern New Zealand

“…Sampling was concentrated during October and November 2004, as August to November is considered the peak of the reproductive period for banded wrasse (Barrett 1995;Denny & Schiel 2002). From these intensive samplings, 35 fish were sampled to determine fecundity and the number of spawning events per season, six of which were used to determine the threshold diameter at which oocytes are responsive to treatment with gonadotropin or MIH in vitro.…”

“…Banded wrasse are asynchronous spawners that follow the usual labrid seasonal spawning pattern of spring to summer, spawning from July until December (Denny & Schiel 2002). Estimates of fecundity do not currently exist for the banded wrasse (Lyle & Hodgson 2001); however, this information is a prerequisite for management of this species both in Australia and in New Zealand.…”