Pacific Plate Biogeography, with Special Reference to Shorefishes

NUMBER 367
batrachoidids occur in, or are restricted to, a
variety of habitats: freshwater rivers, estuaries,
coral reefs, rocky or shelly marine bottoms,
muddy sand, and in the intertidal, where they
may even be stranded out of water for several
hours without harm. Eggs are deposited in, and
attached to, almost any type compartment: jars,
shells, holes, cans, crevices. Nests are guarded and
the young, upon hatching, are demersal.
Mead (1970) believed that the toadfishes are
distributed worldwide. Toadfishes are widely distributed
latitudinally and longitudinally, but are
notably absent from the Pacific Plate (Figure 6).
The largest numbers of genera and species of
toadfishes are found in the western Atlantic
(seven genera, 25 species, plus three more species
in Atlantic freshwater drainage systems). Only
three genera and about nine species occur in the
Indo-West Pacific, excluding the highly restricted
five endemic genera from southernmost Africa
(Collette and Russo, 1981; Hutchins, 1976). The
apparent absence of toadfishes from most of the
Indian Ocean coast of Africa, and from the coasts
of Madagascar and mainland China is surprising.
BELONIDAE
The needlefishes comprise nine genera and 30
species of epipelagic fishes found in freshwaters,
estuaries, and marine habitats, both inshore and
offshore. Needlefishes have a maximum body
length ranging from 42 mm (two South American
freshwater species) to 950 mm for one worldwide
marine species, Tylosurus acus, which consists of
five well-differentiated subspecies (one western
Atlantic, one Mediterranean, one eastern Atlantic,
one eastern Pacific, and one Indo-Pacific; the
Indo-Pacific subspecies extends eastwards to the
offshore eastern Pacific islands of Cocos and Revillagigedos;
Collette and Parin, 1970). Needlefish
eggs bear entangling filaments and are demersal
unless attached to floating objects (summarized
in Breder and Rosen, 1966).
Cressey and Collette (1971) give distribution
maps for many of the needlefish species. Collette
(pers. comm.) has many more Indo-Pacific records
for Tylosurus acus than are indicated on Cres-
sey and Collette's figure 177, which might otherwise
appear to indicate an example of an Hawaiian
exception distribution.
Strongylura, the most speciose genus of needlefishes,
comprises 13 species, of which two are
strictly freshwater, one estuarine, and ten marine,
many of which ascend freshwaters. Five species
of Strongylura (four marine, one estuarine) occur
in (and are limited to) the Indo-Pacific, but only
one, a marine species {Strongylura incisa), extends
nonmarginally onto the Pacific Plate (Cressey
and Collette, 1971). Strongylura incisa, together
with the four worldwide species (Ablennes hians,
Platybelone argalus, Tylosurus acus, T. crocodilus),
make a total of five species of needlefishes present
on the Pacific Plate.
Aside from the two worldwide species of Tylosurus,
there are three other species of Tylosurus: T.
choram, known only from the Red Sea and northwestern
Indian Ocean, T. gavialoides from northern
Australia, and T. punctulatus, from the Malayan
and Philippine area. The five species of
Tylosurus, the five marine and estuarine species of
Strongylura, and the monotypic Ablennes and Platybelone
comprise the 12 species of needlefishes
found in the Indo-West Pacific.
BLENNHDAE
The blennies are a circumglobal family that
comprises five tribes, 54 genera, and about 300
species of small (maximum adult sizes ranging
from about 15 to 532 mm SL, but few exceed 150
mm), predominently near-shore, benthic fishes.
Most of the species are restricted to warm marine
waters, but a few species occur in temperate
marine or warm freshwaters. As far as known, all
the species are nest builders, and although prejuveniles
of several species may occur planktonically
a short distance offshore, the unmetamorphosed
young are generally taken with the adults.
Individuals of a few species have been taken
around floating sargassum or other objects, and
one Indo-West Pacific species {Omobranchus punctatus),
of an otherwise Indo-Pacific restricted genus,
occurs in the Caribbean, possibly as a result
of an introduction (Springer and Gomon, 1975).
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