Size at the onset of sexual maturity in femaleJasus edwardsii(Decapoda: Palinuridae) in New Zealand

Abstract

The size at the onset of sexual maturity for female rock lobsters, Jasus edwardsii, was defined as the size or size class at which 50% of the rock lobsters in a sample were mature, and was estimated at 27 localities around New Zealand. Animals were regarded as mature if they were bearing external eggs attached to the pleopods or if there were well developed setae on the endopodites of the pleopods. Samples from the same location in different years showed little variation in the size at the onset of maturity. There was, however, considerable variation between localities, ranging from 72 mm carapace length near Gisborne to 121 mm carapace length in eastern Foveaux Strait. Size at the onset of maturity showed an inverse relationship with water temperature. The relationship between the size at the onset of maturity, age, growth rate, and water temperature is discussed.

Maturidade sexual em Callinectes ornatus Ordway, 1863 (crustacea: decapoda: portunidae) no litoral de Ilhéus, BA, Brasil

“…Hines (1989) encontrou padrão semelhante para as espécies Pachygrapsus crassipes Randall, 1840; Panopeus herbstii H. Milne Edwards, 1834; e Hemigrapsus oregonensis (Dana, 1851). Este fato pode estar relacionado às taxas de crescimento diferenciadas por variação latitudinal de fatores ambientais como a temperatura e sua interação com o fotoperíodo (Giese, 1959;Annala et al, 1980;Jones & Simons, 1983).…”

Size at onset of breeding in femaleJasus verreauxi(Decapoda: Palinuridae) in New Zealand

“…edwardsii, the presence of setae equates well with the presence of mature ovaries. Furthermore the low percentage of setose females without eggs during the egg-bearing season suggests a high correlation between the presence of setae and the bearing of eggs for this species (Annala et al 1980).…”

“…The most widely used of these indicators in New Zealand have been the presence or absence of well-developed setae on the endopodites of the pleopods, and the presence or absence of external eggs (Bradstock 1950;Street 1969;Annala et al 1980 for Jasus edwardsii; Kensler 1967a for Jasus verreauxi (H. Milne Edwards)). Kensler 1967(a) examined female J. verreauxi from Spirits Bay in October and December 1966, and concluded that 50% or more were mature at a rostral carapace length (RCL) of 155 mm and greater.…”

Does pleopod setation provide a measure of maturity in female southern rock lobsters <i>Jasus edwardsii</i>?

“…This simple observation is important for fisheries research on rock lobsters as SOM is typically estimated from data collected throughout the year as part of catch sampling programs. Analyses that use data from a range of seasons and assume no seasonal effect have been used as evidence of spatial and temporal differences in SOM (Annala et al, 1980;Polovina, 1989). This risk of seasonal variation in SOM biasing conclusions has recently been addressed in the development of protocols for estimating SOM in clawed lobsters (DFO Canada, 2003), and a similar need for consistent timing in data collection appears to exist for spiny lobsters.…”

“…Annala et al, 1980) allows maturity to be established with certainty and is not affected by the ability of the female to successfully mate and produce external eggs. However, this method is time-consuming and destructive, and female size is recorded prior to the winter moult and egg extrusion (in Jasus species in which egg extrusion is shortly after moulting; MacDiarmid, 1989a).…”