140 
B, three unidentified species of Trachonurus and 
Bathygadus cottoides have the greatest number of 
specimens; several species of the genera 
Caelorinchus, Coryphaenoides, Nezumia and 
Ventrifossa are also well represented. Several 
species account for the prominence of the 
Alepocephalidae. In 800-1000 m Xenodermichthys 
copei and Rouleina guentheri are the most abundant 
(10% and 3% respectively); in the two deepest 
strata Alepocephalus triangularis, A. cf. produdus and 
Narcetes lloydii each make up between 1 and 4% of 
numbers. Oreosomatids are represented by four 
species, but Allocyttus verrucosus is the most 
abundant, making up 10% and 12% of numbers in 
the 800-1000 m and 1000-1200 m strata, 
respectively. The Synaphobranchidae, comprising 
four species, ranks fourth and third in the two 
deepest strata (1000-1200 m and 1200-1400 m). 
Diastobranchus capensis and Synaphobranchus 
brevidorsalis are most numerous with a combined 
proportion of about 7% of numbers in each 
stratum; S. affinis and S. kaupi contribute about 3% 
of the total number of individuals between 1000- 
1200 m. Neoscopelus macrolepidotus (Neoscopelidae) 
accounts for 10% of the total number of specimens 
taken in the 800-1000 m stratum and Bathypterois 
ventralis (Bathypteroidae) 7% of the numbers in the 
1200-1400 m stratum. 
Other groups are prominent in terms of species 
numbers or biomass but account for relatively few 
individuals. Overall, the Squalidae, with 22 
species, ranks second in terms of numbers of 
species and, in the six strata sampled, ranks 
eleventh, sixth, ninth, seventh, eighth and eleventh, 
respectively, in numbers of individuals. Squalus 
megalops and S. mitsukurii are the dominant 
squalids on the upper-slope (1-3% and -1% of 
numbers, respectively), with Deania calcea relatively 
common (-1%) on the shallow mid-slope, and 
Zameus squamulosus widespread and relatively 
common (-1%) in the 800-1500 m range. The 
Triglidae is represented by 13 species, dominated 
by members of Lepidotrigla and Satyrichthys. This 
family is restricted mainly to the shallow and mid¬ 
range of the upper-slope with only the distribution 
of S. cf. investigatoris extending below 500 m. 
Representatives of the Ophidiidae range from the 
upper-slope to the deep mid-slope. The upper- 
slope species, Dannevigia tusca and Genypterus 
blacodes, are relatively large but rare in this region, 
whereas several of the deep-dwelling species are 
more numerous and contribute to the prominent 
ranking of this family (fifth and seventh) in the two 
deepest strata. In these strata, the dominant 
species, Monomitopus sp. A, accounts for -1-3% of 
total numbers of individuals. 
Dominant taxa at different latitudes 
The shallow upper-slope (-200-400 m) fauna 
A. Williams, P.R. Last, M.F. Gomon, J.R. Paxton 
north of Shark Bay includes many tropical Indo- 
West Pacific species and species whose 
distributions include the outer shelf area of 
northwestern Australia (e.g., Sainsbury el al. 1985). 
The most abundant components in survey trawls 
include Dentex tumifrons, Acropoma japonicum, 
Malakichthys sp. A, Synagrops philippinensis and 
Nemipterus bathybius; commercial catches from this 
region are dominated by the lutjanid Etelis 
carbunculus with a by-catch of other tropical 
lutjanids, serranids and priacanthids. The shallow 
upper-slope fauna south of Perth comprises mainly 
temperate fishes whose distributions also 
encompass the outer shelf. Dominant elements 
include Dannevigia tusca, Neosebastes thetidis, 
Pterygolrigla polyonmata, Neoplatycephalus conatus, 
Lepidoperca filamenta, Zanclistius elevatus, 
Oplegnathus woodxvardi, Nemadadytus macropterus, 
and Nelusetta ayraudi. 
A similar overlap of warm and cool water 
species is evident on the deeper reaches of the 
upper-slope (-400-800 m), but the most abundant 
species are generally more widely distributed. 
Abundant tropical/sub-tropical species include 
Synagrops japonicus, Setarches guentheri, Epigonus 
macrops, Bathyclupea sp. A and Champsodon cf. 
longipinnis. The dominant temperate elements of 
the deeper upper-slope fauna include some species 
which did not occur further north than the 
southernmost section of the west coast, and others 
which ranged northward well into warm waters. 
The former group includes several species endemic 
to southern Australia (e.g., Galeus boardmani, 
Urolophus expansus and Lepidoperca filamenta), and 
other species with restricted southern Australian 
and New Zealand distributions (Chlorophthalmus 
nigripinnis, Caelorinchus maurofascialus, 
Lepidorhynchus denticulatus and Helicolenus cf. 
percoides). Temperate species with distributions 
extending into waters north of Shark Bay (~26°S) 
include Hoplostethus latus, Penlaceros decacanthus, 
Zenopsis nebulosus and Notopogon xenosoma. Other 
abundant species have temperate/subtropical 
distributions; Caelorinchus minis, Apogonops 
anomolous, Rexea solandri, Euclichthys polynemus, 
Tripterophycis gilchristi and Malacocephalus laevis. 
Fishes from mid-slope depths (-800-1500 m) are 
typically wide ranging with southern circumglobal, 
Indo-Atlantic or cosmopolitan distributions. Some, 
however, exhibit restricted latitudinal ranges, 
primarily confined to the region between Cape 
Leeuwin and Shark Bay. Tropical mid-slope species 
that are both abundant and have restricted 
distributions include Anacanthobatis sp. A, 
Bathypterois guentheri, B. ventralis, Lamprogrammus 
cf. niger and Mataeocephalus acipenserinus. The 
abundant, wide-ranging species are Pavoraja sp. B, 
Synaphobranchus brevidorsalis, Aldrovandia affinis, A. 
phalacra, Alepocephalus triangularis, Xenodermichthys 
