458
N. BALAKRISHNAN NAJR AND M. SARASWATHY
facilitates the rapid settlement. A gregarious tendency has also been
reported (Nagabhushanam, 1959a), a distinctly greater number settling
on experimental panels previously infested with the adult borers than
on the controls. Contrary to the findings of Nagabhushanam (1959a)
Karande et al. (1968) noted that the settlement of T . furcifera in Bombay harbour was independent of both light intensity and the presence
of a primary film comprised of bacteria, algae or fungi since larvae
settled and grew even on sterilized, " clean " timber blocks, the latter
being maintained in sterilized sea water for a number of days. According to Karande et al. (1968) it is the softening effect of sea water, rather
than the microfilm that helps borer larvae to abrade the wood.
G. Marine fungi and shipworm attack
Wood infesting bacteria and fungi, especially in the Ascomycetes and
in the Deuteromycetes (Fungi imperfecti), participate in a sort of
" conditioning " of the timber, preparing it for the subsequent attack by
borers. This is a biological phenomenon, the importance of which has
only recently been stressed (Becker and Kohlmeyer, 1958 ; Kohlmeyer,
1963). The activity of these fungi leads t o wood deterioration called
" soft-rot ". They are resistant to preservatives and release a strong
cellulase which hydrolyses the dignified cell elements leading to the
softening and disintegration of the outer tissues of timber. Even though
the damage is not spectacular, and may not even be noticed by the
layman, their steady activity following submergence prepares timber
for attack by crustacean and molluscan borers. These in turn help the
fungi to spread from superficial layers to the very core of the timber.
Fungal infestation on light timbers of catamarans, dug-out canoes and
other fishing crafts, according to Becker and Kohlmeyer (1958), is not
of the usual superficial type, the penetration being deep, affecting the
entire log. The periodic drying of these logs accelerates the spread of
the fungal hyphae which get effective ventilation through the large
vessels of these light timbers. Our studies at Cochin harbour have revealed the existence of the following species of marine fungi in the
timber test panels. Gnomonia longirostris Cribb and Cribb, Halosphaeria
quadricornuata Cribb and Cribb, Torpedospora radiata Meyers, Corollospora pulchella Kohlm., Schmidt and Nair, and Lulworthia sp. (Nair,
1968). The exact role played by these fungi in the ecology of shipworms is under investigation.
Recent work on the fungal deterioration of wood in the sea includes
taxonomic studies by Cavaliere (1968), Hughs (1968), Johnson (1968),
Kirk (1969 b), Kohlmeyer (1968 a, b, c, d), and Tubaki (1968, 1969) and
N. BALAKRISHNAN NAJR AND M. SARASWATHY
facilitates the rapid settlement. A gregarious tendency has also been
reported (Nagabhushanam, 1959a), a distinctly greater number settling
on experimental panels previously infested with the adult borers than
on the controls. Contrary to the findings of Nagabhushanam (1959a)
Karande et al. (1968) noted that the settlement of T . furcifera in Bombay harbour was independent of both light intensity and the presence
of a primary film comprised of bacteria, algae or fungi since larvae
settled and grew even on sterilized, " clean " timber blocks, the latter
being maintained in sterilized sea water for a number of days. According to Karande et al. (1968) it is the softening effect of sea water, rather
than the microfilm that helps borer larvae to abrade the wood.
G. Marine fungi and shipworm attack
Wood infesting bacteria and fungi, especially in the Ascomycetes and
in the Deuteromycetes (Fungi imperfecti), participate in a sort of
" conditioning " of the timber, preparing it for the subsequent attack by
borers. This is a biological phenomenon, the importance of which has
only recently been stressed (Becker and Kohlmeyer, 1958 ; Kohlmeyer,
1963). The activity of these fungi leads t o wood deterioration called
" soft-rot ". They are resistant to preservatives and release a strong
cellulase which hydrolyses the dignified cell elements leading to the
softening and disintegration of the outer tissues of timber. Even though
the damage is not spectacular, and may not even be noticed by the
layman, their steady activity following submergence prepares timber
for attack by crustacean and molluscan borers. These in turn help the
fungi to spread from superficial layers to the very core of the timber.
Fungal infestation on light timbers of catamarans, dug-out canoes and
other fishing crafts, according to Becker and Kohlmeyer (1958), is not
of the usual superficial type, the penetration being deep, affecting the
entire log. The periodic drying of these logs accelerates the spread of
the fungal hyphae which get effective ventilation through the large
vessels of these light timbers. Our studies at Cochin harbour have revealed the existence of the following species of marine fungi in the
timber test panels. Gnomonia longirostris Cribb and Cribb, Halosphaeria
quadricornuata Cribb and Cribb, Torpedospora radiata Meyers, Corollospora pulchella Kohlm., Schmidt and Nair, and Lulworthia sp. (Nair,
1968). The exact role played by these fungi in the ecology of shipworms is under investigation.
Recent work on the fungal deterioration of wood in the sea includes
taxonomic studies by Cavaliere (1968), Hughs (1968), Johnson (1968),
Kirk (1969 b), Kohlmeyer (1968 a, b, c, d), and Tubaki (1968, 1969) and