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Syngnathinae

There are two species of seadragons to be found in Australian waters, the common or weedy seadragon (Phyllopteryx taeniolatus), and the leafy seadragon (Phycodurus eques).

These spectacular fish, along with seahorses, pipehorses and pipefish belong to the family Syngnathidae. Syngnathids are long, slender fish with bony plates surrounding their bodies. They have a long tubular snout and a tough solid hide and their eyes move independently of each other. They have no teeth or stomach and grow to around 30 to 50cm. The weedy seadragon is the only seadragon species confirmed to be found in Tasmania.

The leafy seadragon is usually green gold and orange with appendages that look like leaves (great for camouflage) and is generally more ornate than the weedy seadragon.

T...

Tasmania has a spectacular coastline and diverse marine environment. Seagrass habitats in Tasmania, as elsewhere in the world, have been lost, fragmented and damaged by development and poor catchment management, through practices such as sewage and stormwater discharges, urban runoff, dredging, boating and land reclamation.

Seagrass meadows play a key ecological role in Australia’s coastal ecosystems and the loss of seagrass beds is considered to be one of the most serious issues in Australia’s marine environment. There are thought to be less than 70 species of seagrasses worldwide, about half of which are present around Australia’s 32,000-kilometre coastline. Six marine species of seagrass are recorded around Tasmania, while an additional two species occur in estuaries...

Kyphosidae

Kyphosidae, drummers or sea chubs are coastal reef fishes, found in the warm temperate seas of Australia. There are over 40 species, of which only a limited number will be found in the region. Their diet normally consists of encrusting invertebrate communities and algae but some species, such as the blue maomao and the sweep feed mainly on plankton. Their bodies are thickly built and oval shaped with one dorsal fin. Their body and median fins are covered in small, weakly ctenoid scales (resembling the teeth of a comb).

The southern silver drummer (Kyphosus sydneyanus) has grey body, a dark spot below the pectoral fin base and a large caudal (tail) fin. It grows to 75cm in length and can be found on coastal rocky reefs, in harbours and bays...

Lobsters, like shrimps and crabs, are decapods – literally meaning 10 legs – and can be found in all of the world’s tropical and sub-tropical seas as well as more temperate waters like these around Tasmania and Southern Australia. They are predatory, nocturnal animals with a vividly decorated coat. They are often numerous locally; they linger in crevices (with their long antennae sticking out) during the day and hunt small benthic organisms at night, but they also feed on organic detritus whenever they happen across it. As with all crustaceans, the lobster moults or sheds its shell to grow.

Lobsters have recently suffered a dramatic demographic decline; intensive fishing has annihilated entire populations, especially where tourism abounds.

The lobster families that you may e...

Abalones are slow growing, herbivorous marine snails. They belong to a large class of molluscs (Gastropoda) with singlestructured shells. There are over 100 species worldwide in the single genus Haliotis, which means ‘sea ear’, a reflection of the flattened shape of the shell. It is no surprise then that it is called ‘Oreille de Mer’ in France. Abalone shells can be oval or rounded, with a row of respiratory pores and large dome towards one end.

The strong, muscular foot generates enough suction to allow the abalone to fix itself firmly to rocky surfaces. They are found from the intertidal to the depth limit of marine plants, some 80 -100m, and from tropical to cold waters.

Abalone is an edible mollusc and considered a delicacy...

Lutjanidae

Snappers are a large and diverse group of robust-bodied, carnivorous fishes. Most species possess relatively large mouths with stout canine teeth and bodies covered with relatively large, coarse scales.

Snappers are members of the Lutjanidae family which has 17 genera and 103 species. They are found in the tropical and subtropical waters of the Atlantic, Indian, and Pacific Oceans. Most species of Snappers are carnivorous fish with relatively large mouths and enlarged canine teeth. They tend to swim at deeper depths.

There are over one hundred individual species globally, but within the subtropical waters of Australia there are a limited number of species that you are likely to see at diving depth, and many of these are shown below...

Lobsters, like shrimps and crabs, are decapods – literally meaning 10 legs – and can be found in all of the world’s tropical and sub-tropical seas as well as more temperate waters. They are predatory, nocturnal animals with a vividly decorated coat. They are often numerous locally; they linger in crevices (with their long antennae sticking out) during the day and hunt small benthic organisms at night, but they also feed on organic detritus whenever they happen across it. As with all crustaceans, the lobster moults or sheds its shell to grow.

Lobsters have recently suffered a dramatic demographic decline; intensive fishing has annihilated entire populations, especially where tourism abounds.

The lobster families that you may encounter are the true reef lobsters, Nephropidae, w...

Serranidae

When people talk about coral reefs, fishermen tend to shrug their shoulders and complain about snagged lines and torn nets. But when you talk about groupers, they suddenly sit up and pay attention. Groupers are among the economically most important fishes of the coral reef, because of their popularity as food. Yet without the coral reef there would probably be no groupers. For this reason, groupers are an extremely important indicator species and your record of their existence or non-existence during your dive tells us a lot.

The goliath grouper (Epinephelus itajara), sometimes called the jewfish is classified as critically endangered on the IUCN Red List. Found in shallow, inshore waters to depths of 45m, this indicator prefers areas of rock, coral, and mud bottoms...

Identifying sharks in the wild is a great challenge! While scientists can spend weeks examining every detail of a species, divers may encounter a shark for only a few seconds or minutes. Many species look alike and one individual may not be identical to the next. There are, however, relatively few species in any one specific dive site and with some preparation and a little practice it is possible for all of us to recognise the more common and distinctive species. The key to successful shark identification underwater is a process of elimination, based on a mental checklist of the main features to look for in every animal encountered. One feature alone is rarely enough for a positive identification, so gather as much information as you can before drawing firm conclusions.

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Parastichopus californicus

The California sea cucumber, Parastichopus californicus, is found from the Gulf of Alaska to Baja California, Mexico in the low inter-tidal zone down to 249 meters. This is the largest sea cucumber on the West Coast, up to 20in (50cm) in length when it is relaxed. When it is feeding this species is mobile, having tube feet on its ventral surface. Twenty tentacles at the anterior end of the body secrete a substance which aids in the capture of detritus and small organisms on sand and rock bottoms. The California sea cucumber is taken commercially in Southeast Alaska and Kodiak, and south along the West Coast. The California sea cucumber is in the Phylum Echinodermata and Family Stichopodidae.

Note: Many species of fish and plants are known by diff...