326
P. 9. MEADOWS AND J. I. CAMPBELL
to enchytraeid worms but does not normally attack undamaged
Lymnaea (Hatto, 1968), which might be an inconvenience in the field
as there may not be many damaged Lymnaea available. Their
preference for damaged Lymnaea was confirmed by Y tube experiments.
The North American water bug, Notoneeta un&ulata Say, is an important
predator of mosquito larvae and pupae and Ellis and Borden (1970)
have shown that it has a well-defined preference for these over other
prey organisms.
Amongst other invertebrates certain nudibranchs are known to feed
on sea anemones and they also respond in a Y tube to water that has
passed over their natural food (Braams and Geelen, 1953 ; Stehouwer,
1964; Van Haaften and Verwey, 1959). Using similar techniques,
Castilla and Crisp (1970) have reinvestigated the chemical basis of
feeding and predator avoidance of Asterias rubens L. The oyster drill
Urosalpinx cinerea (Say) responds to substances released into sea water
by its prey Crmsostrea virginim and Modiolus demissus Dillwyn and its
response is greater to individuals having a higher respiratory rate
(Blake, 1960). Blake goes on to suggest that Urosalpinx may be able
to select a particular individual from within a group because that
individual has a higher respiratory rate and hence is producing more of
some hypothetical metabolic product. It would seem more reasonable
to suggest that the Urosalpinx could be attracted t o the oyster around
which the level of attractant (metabolic product) is highest because
of the higher respiratory rate. It is di6cult to see how this can operate
in field conditions and of what advantage it is to the Urosalpinx t o be
able to detect perhaps small differences in levels of concentration of
attractant in an area which may contain many oysters.*
Other studies on feeding by carnivorous marine invertebrates are
those of Lindberg (1955), which is an essentially descriptive account of
foraging behaviour by the spiny lobster Panulirzls interrqtus (Randall),
of Matthews (1955), which briefly proves that the sand crab Hippa
pacifica Dana detects its preferred food, the Portuguese man-of-war
(Physalia utriculus = P . physalis L.) by a chemical sense, of Shelton
and Mackie (1971) which is concerned with the chemical basis of feeding
in Carcinus maenas (L.), of Brun (1972) on the feeding habits of Luidia
ciliaris (Philippi), and of Landenberger (1966, 1967, 1968), which is an
experimental analysis of the feeding of the Pacific starfish Pisaster.
Landenberger's detailed studies serve as a model for future research
in this field, and some of his results will be summarized here. Pisaster
giganteus (Stimpson) feeds on a wide variety of animals, but mainly
on molluscs. In one particular area it is very abundant under and on the
*See note added in proof on page 493.
P. 9. MEADOWS AND J. I. CAMPBELL
to enchytraeid worms but does not normally attack undamaged
Lymnaea (Hatto, 1968), which might be an inconvenience in the field
as there may not be many damaged Lymnaea available. Their
preference for damaged Lymnaea was confirmed by Y tube experiments.
The North American water bug, Notoneeta un&ulata Say, is an important
predator of mosquito larvae and pupae and Ellis and Borden (1970)
have shown that it has a well-defined preference for these over other
prey organisms.
Amongst other invertebrates certain nudibranchs are known to feed
on sea anemones and they also respond in a Y tube to water that has
passed over their natural food (Braams and Geelen, 1953 ; Stehouwer,
1964; Van Haaften and Verwey, 1959). Using similar techniques,
Castilla and Crisp (1970) have reinvestigated the chemical basis of
feeding and predator avoidance of Asterias rubens L. The oyster drill
Urosalpinx cinerea (Say) responds to substances released into sea water
by its prey Crmsostrea virginim and Modiolus demissus Dillwyn and its
response is greater to individuals having a higher respiratory rate
(Blake, 1960). Blake goes on to suggest that Urosalpinx may be able
to select a particular individual from within a group because that
individual has a higher respiratory rate and hence is producing more of
some hypothetical metabolic product. It would seem more reasonable
to suggest that the Urosalpinx could be attracted t o the oyster around
which the level of attractant (metabolic product) is highest because
of the higher respiratory rate. It is di6cult to see how this can operate
in field conditions and of what advantage it is to the Urosalpinx t o be
able to detect perhaps small differences in levels of concentration of
attractant in an area which may contain many oysters.*
Other studies on feeding by carnivorous marine invertebrates are
those of Lindberg (1955), which is an essentially descriptive account of
foraging behaviour by the spiny lobster Panulirzls interrqtus (Randall),
of Matthews (1955), which briefly proves that the sand crab Hippa
pacifica Dana detects its preferred food, the Portuguese man-of-war
(Physalia utriculus = P . physalis L.) by a chemical sense, of Shelton
and Mackie (1971) which is concerned with the chemical basis of feeding
in Carcinus maenas (L.), of Brun (1972) on the feeding habits of Luidia
ciliaris (Philippi), and of Landenberger (1966, 1967, 1968), which is an
experimental analysis of the feeding of the Pacific starfish Pisaster.
Landenberger's detailed studies serve as a model for future research
in this field, and some of his results will be summarized here. Pisaster
giganteus (Stimpson) feeds on a wide variety of animals, but mainly
on molluscs. In one particular area it is very abundant under and on the
*See note added in proof on page 493.