430
N. BALAKRISHNAN NAIR AND M. SARASWA!lV3Y
of wooden ships, wooden sea water tanks of ships and log-booms (see
Kirkbride, 1922 ; Moll, 1936, 1936a). Rapid increase in maritime ship
ping in the past two centuries helped this transport (Kofoid et al.,
1927). The European species reached American shores during World
War I (Brown, 1935). Ships transported at least one species to South
Africa, China, Japan and Australia (Moll, 1936, 1948). It is also true
that infested driftwood carried by the surface currents played a major
role in their wide distribution (Moll, 1940, 1941). Floating nuts and
seeds drifting passively in the surface currents distributed at least one
nut-infesting species in the region between the east coast of Africa and
the Philippines (Moll, 1936, 1948; Moll and Roch, 1937). From the
Philippines and neighbouring areas many species have reached Hawaii
in driftwood (Moll, 1941) and in light ocean-going craft of wooden construction (Edmondson, 1946a, 194613, 1962 ; Mawatari, 1950). The whole
Indo-west Pacific area contains many common species (vide Table 111).
There is also the possibility of the release of larvae from infested waterlogged wood lying on the sea bottom. This picture of wide distribution
can be explained either on the basis of passive dispersal of free-swimming larvae and of adults through prevailing surface currents and drif'twood respectively or through the active transport of adults by ships.
Thus a few tropical species such as Bankia carinata, B. campanellah
and B. bipennata have succeeded in establishing themselves around the
world in both tropical and subtropical waters. It has also been noted
that the larvae can be effectively transported amidst the thick growth
of fouling organisms that accumulate over the bottoms of the steel
hulls of ships. A curious means of transport of larvae within the body
of a fouling organism has also been recorded. Larvae taken in with the
feeding current in one locality by a worm attached to a ship passed
through the alimentary canal apparently undamaged and emerged
alive along with the faecal pellets of the worm when the ship reached
another locality (see Turner, 1966). These observations reveal that
several species of shipworms have been dispersed, and others may be
expected to be so, over wide areas of the oceans. Edmondson (1962)
reports that certain shipworms can spend the life cycle from larva to
adult in the open sea supported by some suitable flotsam without
making contact with stationary structures in coastal waters. The
larvae of these " seasoned ocean travellers " can endure long enough to
contact drifting timber and continue a chain of seafaring generations..
As pointed out by Edmondson (1946) while specimens from drift
logs and wooden hulls may serve as a legitimate record of the locality,
they may not represent established fauna. Conditions must be sufficently suitable for spawning, for the survival of the larvae and success-
N. BALAKRISHNAN NAIR AND M. SARASWA!lV3Y
of wooden ships, wooden sea water tanks of ships and log-booms (see
Kirkbride, 1922 ; Moll, 1936, 1936a). Rapid increase in maritime ship
ping in the past two centuries helped this transport (Kofoid et al.,
1927). The European species reached American shores during World
War I (Brown, 1935). Ships transported at least one species to South
Africa, China, Japan and Australia (Moll, 1936, 1948). It is also true
that infested driftwood carried by the surface currents played a major
role in their wide distribution (Moll, 1940, 1941). Floating nuts and
seeds drifting passively in the surface currents distributed at least one
nut-infesting species in the region between the east coast of Africa and
the Philippines (Moll, 1936, 1948; Moll and Roch, 1937). From the
Philippines and neighbouring areas many species have reached Hawaii
in driftwood (Moll, 1941) and in light ocean-going craft of wooden construction (Edmondson, 1946a, 194613, 1962 ; Mawatari, 1950). The whole
Indo-west Pacific area contains many common species (vide Table 111).
There is also the possibility of the release of larvae from infested waterlogged wood lying on the sea bottom. This picture of wide distribution
can be explained either on the basis of passive dispersal of free-swimming larvae and of adults through prevailing surface currents and drif'twood respectively or through the active transport of adults by ships.
Thus a few tropical species such as Bankia carinata, B. campanellah
and B. bipennata have succeeded in establishing themselves around the
world in both tropical and subtropical waters. It has also been noted
that the larvae can be effectively transported amidst the thick growth
of fouling organisms that accumulate over the bottoms of the steel
hulls of ships. A curious means of transport of larvae within the body
of a fouling organism has also been recorded. Larvae taken in with the
feeding current in one locality by a worm attached to a ship passed
through the alimentary canal apparently undamaged and emerged
alive along with the faecal pellets of the worm when the ship reached
another locality (see Turner, 1966). These observations reveal that
several species of shipworms have been dispersed, and others may be
expected to be so, over wide areas of the oceans. Edmondson (1962)
reports that certain shipworms can spend the life cycle from larva to
adult in the open sea supported by some suitable flotsam without
making contact with stationary structures in coastal waters. The
larvae of these " seasoned ocean travellers " can endure long enough to
contact drifting timber and continue a chain of seafaring generations..
As pointed out by Edmondson (1946) while specimens from drift
logs and wooden hulls may serve as a legitimate record of the locality,
they may not represent established fauna. Conditions must be sufficently suitable for spawning, for the survival of the larvae and success-