Demersal continental slope fish fauna off WA 
RESULTS 
Faunal overview 
A total of 388 fish species from 108 families are 
recorded from the western continental slope region 
between the 200 and 1500 m isobaths (Appendix 
1). A high number, around 100 species, are 
recorded from Australian waters for the first time, 
and many are undescribed. 
The most species-rich family is the Macrouridae 
with 50 species; in our collections it has about 2.5 
times the number of species of any other family 
and accounts for about one seventh of all species 
caught. Other speciose families, in decreasing order 
of numbers of species taken, are the Squalidae (22 
species), Alepocephalidae (17), Ophidiidae (17), 
Moridae (13), Triglidae (13), Scyliorhinidae (10) 
and Scorpaenidae (10). Of the remaining families, 
44, or over 40% of the total, are represented by 
only a single species. The composition of dominant 
families changes markedly in the shallower strata 
(200-600 m) but is dominated in depths exceeding 
800 m primarily by macrourids, alepocephalids 
and oreosomatids (Table 3). 
Dominant taxa within depth strata 
Within the shallow upper-slope depth range 
(200-400 m) the numerically dominant families are 
the Acropomatidae, Trachichthyidae, and 
Macrourocyttidae (Table 3). Acropomatids are 
primarily Malakichthys sp. A, Acropoma japonicum, 
Apogonops anomlous and Synagrops philippinetisis 
(-36%, 9%, 3% and 2% of total individuals, 
respectively). Trachichthyid representatives 
include Gephyroberyx darwini (23%) and a suite of 
small Hoplostethus species dominated by H. latus 
139 
(less than 1%). The Macrurocyttidae is represented 
by a single species, Zenion sp. A. 
The Chlorophthalmidae is the dominant family 
in the 400-600 m stratum but represents only 20% 
of individuals. Of the five species collected, 
Chlorophthalmus nigripinnis and Chlorophthalmus sp. 
C are most numerous (13% and 6%, respectively) 
and, as with the other chlorophthalmid species, are 
restricted to the shallow and mid-depths of the 
upper-slope. The prevalence of the Acropomatidae 
in this depth range is due to Apogonops anomolus 
(13%) and Malakichthys sp. A (3%). The 
Scorpaenidae is among the most speciose families 
taken on the western slope region. It is represented 
by several species in this depth range with 
Helicolenus barathri accounting for about 7% of 
individuals. The most abundant macrourids in this 
depth range are Caelorinchus species, the most 
numerous being C. maurofasciatus, C. minis and C. 
parvifasciatus. 
Macrourids are numerically dominant in depths 
below 600 m. Caelorinchus maurofasciatus (11%), 
Malacocephalus laevis (8%), Nezutnia sp. A (6%), 
Ventrifossa macropogon (6%) and Lepidorhynchus 
denliculatus (2%) have the highest numbers of 
individuals in 600-800 m. The species with the 
highest number of individuals is Bathyclupea sp. A 
(Bathyclupeidae), accounting for about 20% of the 
total catch. The Chaunacidae is represented mostly 
by Chaunax cf. fimbriatus (8%) and the 
Neoscopelidae by an unidentified species, 
Neoscopelus sp. A (4%). 
In depths greater than 800 m the Macrouridae is 
the most speciose family, accounting for between 
41% and 50% of the individuals in each of the three 
mid-slope strata. Cetonurus globiceps, Gadomus sp. 
Table 3 Numerically dominant four families in each 200 m depth stratum. Figures are the percentage of the total 
number of individuals per stratum (based on survey data only). 
Depth stratum (m) 
200- 
400- 
600- 
800- 
1000- 
1200- 
400 
600 
800 
1000 
1200 
1400 
Acropomatidae (temperate sea basses) 
50 
17 
Trachichthyidae (sawbellies) 
24 
Macrurocyttidae (dwarf dories) 
5 
Gempylidae (snake mackerels) 
3 
Chlorophthalmidae (greeneyes) 
20 
Scorpaenidae (scorpionfishes) 
10 
Macrouridae (grenadiers) 
8 
42 
41 
50 
49 
Bathyclupeidae (bathyclupeids) 
19 
Chaunacidae (coffinfishes) 
8 
Neoscopelidae (new lantemfishes) 
6 
10 
Oreosomatidae (oreo dories) 
10 
12 
Alepocephalidae (slickheads) 
14 
12 
7 
Synaphobranchidae (basketwork eels) 
10 
7 
Ipnopidae (tripodfishes) 
7 
Mean number of fish per standard trawl 
3229 
510 
223 
202 
157 
160 
Number of samples 
12 
12 
10 
15 
11 
5 
