779 
Abstract .“The age, growth, and re- 
production of the tropical Indo-Pacific 
ommastrephid squid Nototodarus 
hawaiiensis was studied on the North 
West Slope of Australia. The weight, 
mantle length ( ML ), gonad weight, and 
nidamental gland length were mea- 
sured for 37 males and 52 females cap- 
tured in January and February 1992 
and ranging in size from 42 mm ML to 
214 mm ML. Statolith increments were 
counted, as a proxy for age. The num- 
ber of statolith increments, counted on 
42 of the squid, ranged from 49 to 195. 
The relation between increment num- 
ber (i.e. age) and ML was linear for both 
sexes. The relation between increment 
number and ovary weight, and between 
increment number and testis weight, 
had greater variability than did ML 
versus ovary weight, and ML versus 
testis weight, indicating a large range 
in age at maturity in individuals of 
similar size. Some statoliths showed 
two prominent zones, the origins of 
which are uncertain. Back-calculated 
hatch dates indicated that all squid 
hatched between July and December 
1991 and that the majority hatched 
between August and October (Austral 
spring). 
Manuscript accepted 7 January 1998. 
Fish. Bull. 96:779-787 (1998). 
Age, growth, and reproduction of the 
tropical squid Nototodarus hawaiiensis 
(Cephalopoda: Ommastrephidae) 
off the North West Slope of Australia 
George D. Jackson 
Department of Marine Biology, James Cook University 
Townsville, Queensland 4811, Australia 
Present address: University of Tasmania 
Institute of Antarctic and Southern Ocean Studies 
Hobart, Tasmania 7000, Australia 
E-mail address: george.jackson@jcu.edu.au 
Vicki A. Wadley 
CSIRO Division of Marine Research 
GPO Box 1538, Hobart Tasmania 7001, Australia 
Nototodarus hawaiiensis (Berry, 
1912) was thought originally to be 
restricted to the Hawaiian Islands 
in the central Pacific (Roper et al., 
1984). However, studies by Dunning 
(1988a, 1988b) revealed that this 
species is also distributed in the 
Indo-Pacific including the Philip- 
pines (previously referred to as N. 
sloani philippinensis [Voss, 1962]), 
northern Australia, South China 
Sea, western Indian Ocean, and off 
Chile (Dunning and Forch, in 
press). In Australian waters, post- 
paralarval N. hawaiiensis inhabit 
slope waters at depths between 200 
and 500 m off the North West Slope 
and between 100 and 600 m off the 
north east coast to southern Queens- 
land (Dunning, 1988b) in bottom 
temperatures of 12.4°C. Recent 
trawl surveys on the North West 
Slope of Australia have shown that 
N. hawaiiensis is the dominant spe- 
cies of cephalopod in commercial 
catches from demersal trawlers 
(Wadley, 1993). The recent identifi- 
cation and dominance of N. hawai- 
iensis in waters off the North West 
Slope of Australia necessitates under- 
standing the biology and role of this 
species in deepwater marine commu- 
nities in tropical Australian waters. 
This study was carried out to ob- 
tain preliminary age, growth, and 
reproductive parameters for N. 
hawaiiensis not previously reported. 
Statolith age analysis, a valuable 
tool in squid growth and life history 
studies (Jackson, 1994), was carried 
out as an indication of age and 
growth. Previous statolith ageing 
work on tropical Australian squid 
species has been restricted to shal- 
low water loliginids that predomi- 
nantly complete their life span in less 
than 200 d (Jackson, 1990; Jackson 
and Choat, 1992; Jackson and Yeat- 
man, 1996). However, no growth in- 
formation has been available to 
date for deepwater tropical species of 
other families. It was therefore of in- 
terest, for comparative purposes, to 
obtain life history parameters of this 
deepwater tropical ommastrephid. 
Statoliths of AT hawaiiensis were 
studied to assess if periodic incre- 
ments might be useful for ageing 
this species. Owing to the difficulty 
of obtaining live specimens from 
deep water, age information has to 
be inferred (as in this study), rather 
than validated on living squid. Incre- 
ment structure was considered in re- 
lation to the validation evidence 
available for other ommastrephids. 
