Size at onset of maturity and size-dependent reproductive output of female and male spiny lobsters Jasus edwardsii (Hutton) (Decapoda, Palinuridae) in northern New Zealand

Seasonal changes in depth distribution, sex ratio and size frequency of spiny lobster Jasus edwardsii on a coastal reef in northern New Zealand

“…However, in other areas the exact timing of these annual cycles, the depth range over which they occur, and the horizontal extent of inshore-offshore movement are likely to b e different from those observed in this study. This is because of latitudinal and size-dependent variations in the timing of moulting and reproduction (Street 1969, McKoy & Esterman 1981, Lipcius 1985, MacDiarmid 1989a, and differences in the depth range of suitable habitats (e.g. Bailey et al 1985) and major prey species (e.g.…”

Plausible causes for sperm-store variations in the coconut crab Birgus latro under large male‑selective harvesting

“…. In some species, larger males have larger sperm reserves (MacDiarmid 1989, Pitnick 1996, Kendall et al 2001, Sato et al 2005, Sainte-Marie et al 2008) and pass larger ejaculates to successive mates than do smaller males (Jivoff 1997. Thus, overall, sperm supply is likely reduced in populations containing only small males.…”

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

“…In addition, maturity data is normally collected as part of larger catch sampling exercises that are not targeted to this specific issue; the use of a secondary indicator of maturity such as pleopod setation enables data to be collected throughout the year. For these reasons, the system of classification of maturity based on ovigerous setae is used by many biologists although, as noted by MacDiarmid (1989a), this carries assumptions that are seldom considered.…”

“…First, we examined the incidence of animals reverting back to a nonsetose state from a setose state following the release of larvae in late Spring (Booth, 1984;MacDiarmid, 1989a). This was examined using the tag recapture history of individual animals from Porkies Break (NW) and Crayfish Point (SE); did any animals change from mature to immature as classified by setal development?…”

“…The Tasmanian regional stock assessment model developed by Punt and Kennedy (1997) would consequently overestimate total egg production in this area, where the minimum legal size of 105 mm CL is much larger than the estimated SOM. MacDiarmid (1989a) suggested that the timing of sampling might bias estimates of SOM where animals are classified as mature on the basis of ovigerous setae. Possible seasonal biases include interactions between maturity, size, movement, catchability and also the periodic loss of setae.…”