Wahoo, Acanthocybium solandri, constitute an economically important fishery for many coastal nations, but assessment of this living marine resource is hampered by a lack of basic life history information. The present study demonstrates that wahoo in the western North Atlantic Ocean are short lived, grow rapidly in their first year, achieve a very large size, and have high mortality rates. The largest individuals were female and the sex ratio was significantly female-biased (298 females: 223 males: 54 unknown sex). An edge analysis showed that annuli formed primarily during winter–spring, which supported the use of sectioned otoliths for ageing wahoo. Wahoo lived a median of 1.3 years, a mean of 1.8 years, and a maximum of 9.3 years (n = 469). They had a high instantaneous mortality rate (Z = 0.98), and they grew rapidly and to a large size; von Bertalanffy growth parameters were: L∞ = 1701 mm fork length (FL), K = 0.381, to = –1.63. Females had a very similar maximum age relative to males (maximum age 9.3 v. age 9.1 years), and they had a slightly, but not significantly, lower mortality (Z = 0.91 v. 1.1) than males. Females grew slightly, although not significantly, larger than males (L∞ = 1797 v. 1555 mm FL, maximum observed = 1804 v. 1585 mm FL). Presumably the piscivorous nature of wahoo feeding, as noted by others, fuels these fast growth rates. Comparative data are very limited but it appears that the survival rate of wahoo in the western Atlantic Ocean is not different now than in the 1960s.

Sixteen study sites across the known north-south range of Pseudomys novaehollandiae in Tasmania were live trapped, and measures of floristic presence and abundance were recorded at each site. Multivariate analysis was used to quantify similarities and differences in plant assemblages at each of the study sites; these included historic sites (sites where P. novaehollandiae had been confirmed to be present 12 years previously) and sites supporting vegetation known to have supported the mouse elsewhere in its range, but from which it had not been recorded. A strong association between P. novaehollandiae capture sites and the occurrence and abundance of the plants Aotus ericoides, Hypolaena fastigiata, Lepidosperma concavum and Xanthorrhoea spp. was found. Nine individual P. novaehollandiae were radio-tracked on one study area to investigate whether the apparent habitat preferences of P. novaehollandiae observed at the population/site level were reflected by individual habitat use. Two individuals were on occasion radio-located in a She-oak stand, a habitat type not typically associated with populations of P. novaehollandiae. Burrow sharing and overlap of home ranges were recorded. Results are interpreted with a view to developing an effective predictive habitat model for P. novaehollandiae in Tasmania.

Epinephelus adscensionis sampled from Ascension Island, South Atlantic Ocean, exhibits distinct life-history traits, including larger maximum size and size at sexual maturity than previous studies have demonstrated for this species in other locations. Otolith analysis yielded a maximum estimated age of 25 years, with calculated von Bertalanffy growth parameters of: L = 55·14, K = 0·19, t = -0·88. Monthly gonad staging and analysis of gonad-somatic index (I ) provide evidence for spawning from July to November with an I peak in August (austral winter), during which time somatic growth is also suppressed. Observed patterns of sexual development were supportive of protogyny, although further work is needed to confirm this. Mean size at sexual maturity for females was 28·9 cm total length (L ; 95% C.I. 27·1-30·7 cm) and no females were found >12 years and 48·0 cm L , whereas all confirmed males sampled were mature, >35·1 cm L with an age range from 3 to 18 years. The modelled size at which 50% of individuals were male was 41·8 cm (95% C.I. 40·4-43·2 cm). As far as is known, this study represents the first comprehensive investigation into the growth and reproduction of E. adscensionis at its type locality of Ascension Island and suggests that the population may be affected less by fisheries than elsewhere in its range. Nevertheless, improved regulation of the recreational fishery and sustained monitoring of abundance, length frequencies and life-history parameters are needed to inform long-term management measures, which could include the creation of marine reserves, size or temporal catch limits and stricter export controls.

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