|
||||
Carnivores |
||||
There are a number of carnivores which live on our shores. Some are swift, efficient hunters, roaming over the rock surfaces hunting down their prey. Fish such as Snapper, Chrysophrys auratus, Yellow Fin Bream, Acathopagrus australis, hunt when the tide is high. The Cyan-coloured Octopus, Octopus cyaneus and Rocky Shore Blue-Ringed Octopus, Hapalochaena sp. which are also found on rocky shores are efficient hunters. If you are fortunate enough to see an octopus hunting down a crab, you will see just how clever and efficient it is. Birds such as the Sooty Oyster Catcher, Haematopus fuliginosus, hunt when the tide is low. There are other hunters too. Not so fast, but no less efficient. I have seen the Reef Crab, Ozius truncatus, eating nematocyst-charged Blue-bottles, Psysalia ultriculus. That would give a "sting" to the meal. There are a number of carnivorous molluscs of various sizes. The largest ones of the low shore, low fringe level and marine zone are the Cart-rut Shell, Dicathais orbita, and Spenglers Rock Whelk, Cabestana spengleri which eats Cunjevoi, Pyura stolonifera. Another smaller, wide ranging carnivorous mollusc is the abundant Mulberry Whelk, Morula marginalba, found on eastern shores. The Mulberry Whelk eats the Common Variegated Limpet, Cellana tramoserica, and a wide range of barnacles including the Six-plated Barnacle, Cthamalus antennatus, Rose-coloured Barnacle, Tesseropora rosea, Surf Barnacle, Catomerus polymerus and others. The Mulberry Whelk has the ability to drill a hole through the shell of their prey, stick their saw-like radula tongue in through the hole, to chop up their prey. They then suck the juices out. It is believed that they place a drop of stomach acid onto the lime of the prey's shell, which assists the carnivore to drill its deadly hole. This process is believed to take only two high tides. The Wine-mouthed Lepsiella, Lepsiella vinosa, and Flinder's Lepsiella, Lepsiella flindersi are small carnivorous molluscs from southern shores. They feed on barnacles and mussels. Many of the worms are effective predators, having mouthparts that lunge outwards to capture unsuspecting prey. Other slow movers, but no-less efficient hunters are the predatory Sea Stars, including the Eleven-armed Sea Star, Cosinasterias calamaria. Some other carnivores do not actively hunt their prey, but wait for a straying animal to come to them. Examples are the anemones, including the Waratah Anemone, Actinea tenebrosa and Sand Anemone, Oulactus muscosa. Anemones have stinging nematocysts and sticky tentacles, which are hard to escape. Parasites:A specialised group of carnivores are the parasites. They do not deliberately kill off their prey, but attach themselves to their host in a way so that they can feed off their tissues, but not actually kill their host. One example is the parasitic barnacle and the Smooth-handed Crab, Pilumnopeus serratifrons. References:Bennett, I. (1987) W. J. Dakin's classic study: Australian Seashores. Angus & Robertson, Sydney. Davey, K. (1998) A Photographic Guide to Seashore Life of Australia. New Holland, Sydney. Edgar, G. J. (1997) Australian Marine Life: the plants and animals of temperate waters. Reed Books, Kew. Quinn, G. P., Wescott, G. C. & Synnot, R. N. (1992) Life on the Rocky Shores of South-eastern Australia: an illustrated field guide. Victorian National Parks Association, Melbourne. Marine Research Group of Victoria (1984) Coastal Invertebrates of Victoria: an atlas of selected species. Museum of Victoria, Melbourne. Shepherd, S. A. & Thomas, I. M. (1982) Marine Invertebrates of Victoria, Pt. 1. South Australian Government Printer, Adelaide. Underwood, A. J. & Chapman, M. G. (1993) Seashores: a beachcomber's guide. New South Wales University Press, Sydney. |
Nutrient
Absorbers Home
Page
|
|||
Life
on Australian Seashores Scientific Consultant: Phil
Colman
|