IV.—The Southern Temperate Zone.
This zone includes the coasts of the southern extremity of Africa, from about 30° lat. S., of the south of Australia with Tasmania, of New Zealand, and the Pacific and Atlantic coasts of South America between 30° and 50° lat. S.
The most striking character of this fauna is the reappearance of types inhabiting the corresponding latitudes of the Northern Hemisphere, and not found in the intervening tropical zone. This interruption of the continuity in the geographical distribution of Shore-fishes is exemplified by species as well as genera, for instance—Chimæra monstrosa, Galeus canis, Acanthias vulgaris, Acanthias blainvillii, Rhina squatina, Zeus faber, Lophius piscatorius, Centriscus scolopax, Engraulis encrasicholus, Clupea sprattus, Conger vulgaris. Instances of genera are still more numerous—Cestracion, Spinax, Pristiophorus, Raja; Callanthias, Polyprion, Histiopterus, Cantharus, Box, Girella, Pagellus, Chilodactylus, Sebastes, Aploactis, Agonus, Lepidopus, Cyttus, Psychrolutidæ, Notacanthus; Lycodes, Merluccius, Lotella, Phycis, Motella; Aulopus; Urocampus, Solenognathus; Myxine.
Naturally, where the coasts of the tropical zone are continuous with those of the temperate, a number of tropical genera enter the latter, and genera which we have found between the tropics as well as in the temperate zone of the Northern Hemisphere, extend in a similar manner towards the south. But the truly tropical forms are absent; there are no Squamipinnes, scarcely any Mullidæ, no Acronuri, no Teuthyes, no Pomacentridæ (with a single exception on the coast of Chili), only one genus of Julidina, no Scarina, which are replaced by another group of Pharyngognaths, the Odacina. The Labrina, so characteristic of the temperate zone of the Northern Hemisphere, reappear in a distinct genus (Malacopterus) on the coast of Juan Fernandez.
The family of Berycidæ, equally interesting with regard to their distribution in time and in space, consists of temperate and tropical genera. The genus by which this family is represented in the southern temperate zone (Trachichthys) is much more nearly allied to the northern than to the tropical genera.
The true Cottina and Heterolepidina (forms with a bony stay of the præoperculum, which is generally armed) have not crossed the tropical zone; they are replaced by fishes extremely similar in general form, and having the same habits, but lacking that osteological peculiarity. Their southern analogues belong chiefly to the family Trachinidæ, and are types of genera peculiar to the Southern Hemisphere.
The Discoboli of the Northern Hemisphere have likewise not penetrated to the south, where they are represented by Gobiesocidæ. These two families replace each other in their distribution over the globe.
Nearly all the Pleuronectidæ (but they are not numerous) belong to distinct genera, some, however, being remarkably similar in general form to the northern Pleuronectes.
With Gadoids Myxinidæ reappear, one species being extremely similar to the European Myxine. Bdellostoma is a genus peculiar to the southern temperate zone.
As in the northern temperate zone, so in the southern, the number of individuals and the variety of forms is much less than between the tropics. This is especially apparent on comparing the numbers of species constituting a genus. In this zone genera composed of more than ten species are the exception, the majority having only from one to five.
The proportion of genera limited to this zone is rather high; they will be indicated under the several districts, which we distinguish on geographical rather than zoological grounds.
1. The Cape of Good Hope district.
The principal genera found in this district are the following (those limited to the entire zone being marked with a single (*) and those peculiar to this district with a double (**) asterisk):—
Chimæra, *Callorhynchus, Galeus, **Leptocarcharias, Scyllium, Acanthias, Rhinobatus, Torpedo, Narcine, Astrape, Raja.
Serranus, Dentex, Pristipoma; Cantharus, Box, **Dipterodon, Sagrus, Pagrus, Pagellus, Chrysophrys; *Chilodactylus; Sebastes, *Agriopus; Trigla; Sphyræna; Lepidopus, Thyrsites; Zeus; Caranx; Lophius; Clinus (10 species), Cristiceps; **Chorisochismus.
*Halidesmus, *Genypterus, Motella.
Syngnathus.—*Bdellostoma.
This list contains many northern forms, which in conjunction with the peculiarly southern types (Callorhynchus, Chilodactylus, Agriopus, Clinus, Genypterus, Bdellostoma) leave no doubt that this district belongs to the southern temperate zone, whilst the Freshwater fishes of South Africa are members of the tropical fauna. Only a few (Rhinobatus, Narcine, Astrape, and Sphyræna) have entered from the neighbouring tropical coasts. The development of Sparoids is greater than in any of the other districts of this zone, and may be regarded as one of its distinguishing features.
2. The South Australian district comprises the southern coasts of Australia (northwards, about to the latitude of Sydney), Tasmania, and New Zealand. It is the richest in the southern temperate zone, partly in consequence of a considerable influx of tropical forms on the eastern coast of Australia, where they penetrate farther southwards than should have been expected from merely geographical considerations; partly in consequence of the thorough manner in which the ichthyology of New South Wales and New Zealand has been explored. On the other hand, the western half of the south coast of Australia is still almost a terra incognita.
The shore-fishes of New Zealand are not so distinct from those of south-eastern Australia as to deserve to be placed in a separate district. Beside the genera which enter this zone from the Tropics, and which are more numerous on the Australian coast than on that of New Zealand, and beside a few very local genera, the remainder are identical. Many of the South Australian species, besides, are found also on the coasts of New Zealand. The principal points of difference are the extraordinary development of Monacanthus on the coast of South Australia, and the apparently total absence in Australia of Gadoids, which in the New Zealand Fauna are represented by six genera.
Shore-fishes of the South Australian district.
| South Australia and Tasmania. | New Zealand. | |
| *Callorhynchus (antarcticus). | 1 | 1 |
| Galeus (canis) | 1 | 1 |
| Scyllium | 2 | 1 |
| **Parascyllium | 1 | — |
| Crossorhinus | 1 | — |
| Cestracion | 2 | 1 |
| Mustelus (antarcticus) | 1 | 1 |
| Acanthias (vulgaris and blainvillii) | 2 | 1 |
| Rhina | 1 | — |
| Pristiophorus | 1 | — |
| **Trygonorhina (fasciata) | 1 | 1 |
| Rhinobatus | 1 | 1 |
| Torpedo | — | 1 |
| Narcine | 1 | — |
| Raja | 3 | 1 |
| Trygon (Urolophus) | 3 | 2 |
| **Enoplosus | 1 | — |
| Anthias (richardsonii) | 1 | 1 |
| Callanthias | 1 | — |
| Serranus | x[29] | — |
| Plectropoma | 4 | — |
| **Lanioperca | 1 | — |
| **Arripis | 3 | 1 |
| Histiopterus | 1 | — |
| Erythrichthys | — | 1 |
| *Haplodactylus | 2 | 2 |
| Girella | 4 | — |
| **Tephræops | 1 | — |
| Pagrus | 1 | 1 |
| *Scorpis | 2 | 1 |
| **Atypichthys | 1 | — |
| **Trachichthys | — | 1 |
| **Chironemus | 1 | 1 |
| **Holoxenus | 1 | — |
| Chilodactylus | 9 | 4 |
| **Nemadactylus | 1 | — |
| **Latris | 2 | 2 |
| Scorpæna | 4 | 2 |
| **Glyptauchen | 1 | — |
| Centropogon | 2 | — |
| *Agriopus | 1 | 1 |
| *Aploactis | 1 | — |
| **Pentaroge | 1 | — |
| Platycephalus | 5 | — |
| Lepidotrigla | 3 | 1 |
| Trigla | 3 | 1 |
| Anema | — | 1 |
| **Crapatalus | — | 1 |
| **Kathetostoma | 1 | 2 |
| **Leptoscopus | 1 | 3 |
| Percis | 2 | 1 |
| *Aphritis | 1 | — |
| Sillago | 2 | — |
| *Bovichthys | 1 | 1 |
| *Notothenia | — | 1 |
| Sphyræna | 1 | — |
| Lepidopus | — | 1 |
| Trichiurus | 1 | — |
| Thyrsites | 1 | 1 |
| **Platystethus | — | 2 |
| Zeus (faber) | 1 | 1 |
| Cyttus | 1 | 1 |
| Trachurus (trachurus) | 1 | 1 |
| Caranx | x | 2 |
| *Seriolella | — | 1 |
| Pempheris | 1 | — |
| Callionymus | 3 | — |
| Batrachus | 1 | — |
| **Brachionichthys | 2 | — |
| **Saccarius | — | 1 |
| Clinus | 1 | 1 |
| **Lepidoblennius | 1 | — |
| Cristiceps and Tripterygium | 4 | 5 |
| **Patæcus | 3 | — |
| **Acanthoclinus | — | 1 |
| **Diplocrepis | — | 1 |
| **Crepidogaster | 3 | 1 |
| **Trachelochismus | — | 1 |
| **Neophrynichthys | — | 1 |
| Centriscus | 2 | 1 |
| Notacanthus (sexspinis) | 1 | 1 |
| **Labrichthys | 8 | 2 |
| **Odax | 5 | 1 |
| Coridodax | — | 1 |
| **Olistherops | 1 | — |
| **Siphonognathus | 1 | — |
| Gadus | — | 1 |
| Merluccius | — | 1 |
| Lotella | — | 1 |
| **Pseudophycis | — | 1 |
| Motella | — | 1 |
| Bregmaceros | — | 1 |
| *Genypterus | 1 | 1 |
| **Lophonectes | 1 | — |
| **Brachypleura | — | 1 |
| Pseudorhombus | — | 1 |
| **Ammotretis | 1 | 1 |
| **Rhombosolea | 3 | 3 |
| **Peltorhamphus | — | 1 |
| Solea | 1 | — |
| Aulopus | 1 | — |
| Gonorhynchus (greyi) | 1 | 1 |
| Engraulis (encrasicholus) | 1 | 1 |
| Clupea | 1 | 1 |
| **Chilobranchus | 1 | — |
| Conger (vulgaris) | 1 | 1 |
| Ophichthys | 1 | 1 |
| Murænichthys | 1 | — |
| Congromuræna | — | 1 |
| Syngnathus | 5 | 2 |
| Ichthyocampus | — | 1 |
| **Nannocampus | 1 | — |
| Urocampus | 1 | — |
| **Stigmatophora | 2 | 1 |
| Solenognathus | 2 | 1 |
| **Phyllopteryx | 2 | — |
| Monacanthus | 15 | 1 |
| Ostracion | 3 | |
| *Bdellostoma | — | 1 |
| Branchiostoma | 1 | 1 |
3. The coast-line of the Chilian district extends over 20 degrees of latitude only, and is nearly straight. In its northern and warmer parts it is of a very uniform character, and exposed to high and irregular tides, and to remarkable and sudden changes of the levels of land and water, which must seriously interfere with fishes living and propagating near the shore. No river of considerable size interrupts the monotony of the physical conditions, to offer an additional element in favour of the development of littoral animals. In the southern parts, where the coast is lined with archipelagoes, the climate is too severe for the majority of fishes. All these conditions combine to render this district comparatively poor as regards variety of Shore fishes, as will be seen from the following list:—
*Callorhynchus; Scyllium, Acanthias, Spinax; Urolophus.
Serranus, Plectropoma, Polyprion, Pristipoma, Erythrichthys; *Haplodactylus; *Scorpis; Chilodactylus, **Mendosoma; Sebastes, *Agriopus; Trigla, Agonus; *Aphritis, *Eleginus, Pinguipes, Latilus, Notothenia (1 sp.) Umbrina; Thyrsites; Trachurus, Caranx, *Seriolella; Porichthys; **Myxodes, Clinus; Sicyases, Gobiesox.
Heliastes; **Malacopterus; *Labrichthys.
Merluccius; *Genypterus; Pseudorhombus.
Engraulis, Clupea; Ophichthys, Muræna.
Syngnathus.—*Bdellostoma.
Of these genera six only are not found in other districts of this zone. Three are peculiar to the Chilian district; Porichthys and Agonus have penetrated so far southwards from the Peruvian and Californian districts; and Polyprion is one of those extraordinary instances in which a very specialised form occurs at almost opposite points of the globe, without having left a trace of its previous existence in, or of its passage through, the intermediate space.
4. The Patagonian district is, with the exception of the neighbourhood of the mouth of the Rio de la Plata, almost unknown. In that estuary occur Mustelus vulgaris, two Raja, two Trygon, several Sciænoids, Paropsis signata and Percophis brasilianus (two fishes peculiar to this coast), Prionotus punctatus, Læmonema longifilis (a Gadoid), a Pseudorhombus, two Soles, Engraulis olidus, a Syngnathus, Conger vulgaris, and Ophichthys ocellatus; and if we notice the occurrence of a Serranus and Caranx, of Aphritis and Pinguipes, and of two or three Clupea, we shall have enumerated all that is known of this fauna. The fishes of the southern part, viz. the coast of Patagonia proper, southwards to Magelhæn’s Straits, are unknown; which is the more to be regretted, as it is most probably the part in which the characteristic types of this district are most developed.