Common Shipwreck Marine Life

Below is a list of the most common marine life found on or around the shipwrecks of our coast. The two sections cover both the Indian Ocean south from Geraldton and the Swan River. Most images are captured by Jacqui, she has always had a passion and knowledge for marine life and capturing images to share through her page                                                        .

Western Rock Lobster (Panilirus cygnus)

Commonly known as crayfish, these cockroaches of the sea call a number of shipwrecks home. Usually foraging at night these creatures favour keeping themselves mostly out of sight under ledges and out of the surge. Some wrecks you can find large nests, others the odd one or two hiding out during the day. The give away for spotting most crays is their long, orange antennae sticking out from under a structure. Some are skiddish and will reverse in deeper to the folds of the wreck, others are more curious and will run their antennae over you and your camera to work out who you are and what you're doing. If you are planning on bagging crays, as some shipwrecks are in sanctuary zones always be aware where you are and of course all the local rules of purchasing a licence and legal sizing, bag limits, tar spots, berrying etc.

Australian Sea Lion (Neophoca cinerea)

 

Sea Lions differ from seals due to visible ear flaps and thicker fur. This particular Sea Lion is the rarest in the world and we are lucky enough to have a colony here in WA. Fishing excursions for these guys can last up to two days so it is very important if you come across them hauling out on a beach, not to disturb them - they need their rest! They feed on fish, squid, octopus, cuttlefish, small sharks and rock lobsters. Males can weigh up to 300kg and these are the only type of Sea Lions or Seals to have an 18 month breeding cycle. 

Quite often when diving the Sepia or Europa (given their close proximity to haul out islands) these inquisitive creatures will give you a buzz by to check you out and see if you're up for a play or a fin nibble. They'll some times mimic you and dart around blowing bubbles, somersaulting and playing amongst each other.

Banded Coral Shrimp (Stenopus hispidis)

Sometimes hard to spot but quite common around the many shallow reef wrecks south of Geraldton are the Banded Coral Shrimp. They hide in cracks and small holes in limestone overhangs during the day then at night they get to work in their cleaning station.

Up to 9cm long and easily recognisable due to their bright, striking red and white bands along the body and third pair of clawed legs. Usually seen in pairs (the male is the smaller of the two) they set up cleaning stations and pick parasites off other fish. Their first and second pairs of claws also possess pincers for cutting and picking up food. The third pair is for display and threat. 

Western King Wrasse (Coris auricularis)

Inquisitive and friendly these fish have been known to follow divers around throughout their dive with particular interest in their bubbles. Wrasse normally school in large groups of females with one male. If something were to happen to that male - such as death or disappearing for a few days, the largest female will incredibly change sex to take the place of the male and so the cycle continues. 

Globefish (Diodon nicthemerus)

When threatened, this type of fish will swallow copious amounts of water to inflate its body. As the body fills and expands, its spines become locked into a ridged, defensive position. The spines are modified scales and their flesh contains the poison tetrodotoxin.  

Particularly common on the HMAS Swan, this species can be found on many wrecks in southern WA.

Octopus

I have stumbled across many octopi on different wrecks and always marvel at their ability to change their appearance to match their environment or communicate messages. How they can quickly change the texture of their skin and colour is simply amazing. They possess eight arms which have two rows of suckers and strong jaws shaped like that of a parrot's beak. They feed mainly on molluscs and crustaceans. When reproducing they produce many thousands of small eggs and the larvae are thought to have a planktonic stage before settling. Adults die after a single reproductive season.

Spotted Wobbegong (Orectolobus maculatus)

Also known as Carpet Sharks due to their flattened bodies and marbled patterns. These sharks are quite tough and muscular and are capable of biting their own tail. Although they appear docile and sluggish don't be fooled, they are extremely quick and should never be handled approached too closely. With a maximum length of 3 metres, this shark screws up its entire body to tear apart and shred its prey.

Most commonly seen on the larger southern wrecks such as the Lena, under the stern of the HMAS Swan, the 26 metre spud foot of the Key Biscayne and corridors of the HMAS Perth.

Western Red Scorpion Fish

These Scorpion Fish can only be found in WA from Point Quobba to Esperance. They can grow to 40 cm long and have poisonous dorsal spines which if stuck by an unsuspecting diver will cause excruciating pain. They are very well camouflaged from bright red to pale brown with a number of tassels on the head and body to help break up the fish's outline. It remains motionless and reluctant to move so watch where you place your hands! The Scorpion Fish will stay motionless for hours waiting for prey to come in range. It will then open its mouth once the prey is close enough and with the sudden intake of water is rushed into the fish's mouth. Common throughout the coastal reef wrecks south of Jurien Bay and almost always found on the wreck sites of Mosman Bay and Black Wall Reach.

Port Jackson Shark (Heterodontus portusjacksoni)

These sharks are distinguishable by the bony crest above the eye, the harness-like arrangement of dark stripes on the body and sandpaper looking skin. This type of shark lays eggs which is commonly referred to as a 'mermaid purse' which is a unique, pronounced spiral flange around a dark brown envelope. The egg incubates for up to 12 months. The pups take up to 10 years to reach maturity at which point they can grow to 1.65 metres.

They are very common amongst the coastal wrecks of Rottnest, Perth and the South West.

Grey Nurse Shark (Archarias taurus)

These sharks have a base colour of greyish-brown to bronze and often have small dark blotches on their bodies which can stretch to 3.2 metres. They have two large dorsal fins and fierce looking, long, curved, fang-like teeth which are usually exposed but don't stress, these sharks are considered harmless to humans. Unlike sharks such as the Port Jackson, (above) the Grey Nurse gives birth to live young. The female has a double-sided uterus and the first egg to hatch in each side of the uterine horn or the strongest fetus, will devour the other eggs or their newly hatched siblings. The two new born pups then have a store of eggs in their stomachs to sustain them over several days after their birth. This species of shark is also protected. These guys are almost always present on the Key Biscayne and are among one of the highlights of the dive.

Telesto Coral (Carijoa species)

This structure is made up of long branches with many large, white polyps. The coral feeds by trapping small particles in its feathery tentacles which are then transported to the central mouth of the polyp. An orange sponge usually grows over the main stems of the colony which gives a great contrast to the white polyps. If you look closely, sometimes there is a well camouflaged nudibranch hiding amoungst the branches. You can spot these colourful corals on the crowsnest of the HMAS Swan and the Stragglers unidentified barge wreck.

Southern Blue Devil (Paraplesiops meleagris)

A hugely attractive fish because of their striking iridescent blue colour which is due to tightly packed bright blue spots on a grey to black or dark blue base. Many also have a brighter blue or purple line around the edges of their fins. Juveniles are a paler blue and can be almost white. They are usually a solitary fish and can be up to 36cm.

Scalyfin

These fish are especially territorial and aggressive when protecting eggs laid in the rocky reef. Many divers have experienced the aggressive rush of the Scalyfin. Adults are a drab brown to black in colouring but the juveniles are quite the opposite with attractive iridescent blue backs and blue lines on a bright yellow body. 

Rough Bullseye (Pempheris klunzingeri)

With large, round eyes these fish vary in colour from a pale pink through to dark orange/brown. Due to the size of their eyes, they have excellent night vision and are often found in huge schools during the day hiding inside shipwrecks, shying away from light. They kind of remind me of the mutants in the movie, 'I Am Legend' when you find them schooled together in an especially dark corner. 

Redlip Morwong (Cheilodactylis rubrolabiatus)

You can find individuals of this species resting under reef ledges, they are very common on the Rottnest wrecks and can span up to 75cm long. They have bright red, rubbery-looking lips with oblique reddish-brown to black bands and dark spots between the bands. 

Common Lionfish (Pterois volitans)

Lionfish can be found from estuaries through to offshore islands and have a maximum length of 35cm. They are regularly found on large enclosed wrecks from Rockingham and further north such as the Key Biscayne and Saxon Ranger. North from Jurien Bay they are extremely common when diving offshore deeper than 15 metres and on the wrecks of the Europa and South Tomi. These fish have variable characteristics for example, some have appendages above the eye that are large and leaf-like and others have next to none. This particular Lionfish is identifiable by its large feathery fins, close banded body pattern, dark spots on its fins and in adults - white spots along the lateral line.

Footballer Sweep (Neatypus obliqus)

Quite an inquisitive fish of white and yellow stripes that enjoys playing in divers' bubbles. They feed on algae and small crustaceans. This fish is found in reefy areas from the central WA coast and south of the continent.

Mosaic Seastar (Pentagoaster duberi)

This starfish can be found on rocky reefs up to 200 metres deep and is common on most wreck sites. The body plan is based on multiples of five; five rows of tube feet, five pairs of reproductive organs and five branches of the digestive tract running down each arm. The central mouth is found underneath the central disc.

Erna's Basket Star (Astroboa ernae)

Multiple arms and long flexible branches form an intricate net-like structure resembling a plant. When I first saw one of these Basket Stars I thought it was some kind of parasite plant trying to strangle the reef beneath it. I had no idea at night, when there are fewer predators, it actually climbs to the highest vantage point of the reef and extends its branches to form a large net so plankton is strained from the water. During the day the branches are tightly curled around the central disc. When fully extended it can reach up to 40cm.

Western Australian Nudibranch

(Chromodoris westraliensis)

Easily my most commonly sighted nudibranch on WA wrecks, this brightly coloured critter can be found all over WA. I have seen them in abundance from Albany to Jurien Bay. Referring to the circle of feathery appendages on their back, the term nudibranch is from the Latin language and means 'naked gills'. All nudibranchs are ‘hermaphroditic’, which means the same animal acts as both male and female. Reproducing as a mating pair, the nudibranchs exchange sperm sacs through a tube. Each nudibranch will then lay egg masses that can contain millions of eggs. 

Batfish

 

Very friendly and curious, Batfish have been known to swim over to divers for a closer inspection. Often seen floating around the top half of wrecks such as HMAS Swan (Dunsborough) and the Lena (Bunbury) they sometimes follow divers up to the 5 metre mark and hang out during the safety stop.

 

Life in the Swan River

Pink Sea Cucumber

Pink Sea Cucumbers will climb to a high vantage point to feed rather than sifting through the silty bottom of the Swan River. They are usually bright pink or yellow and catch food particles on sticky tentacles then curl the tentacle into the central mouth and slurp off the food. They can grow to 11cm long. 

Blue Manna Crab (Portunus pelagicus)

Blue Manna Crabs are large in size and occupy sandy bays and estuaries all around Aus. Easily recognised by their brilliant blue colouring - especially in the males, they have prominent spines on the edge of a flattened carapace of up to 21 cm wide with 10 legs. The first pair of thoracic legs have very large claws used for catching and holding prey and defence. The last pair have a flattened segment on each leg like a paddle which aids in swimming. Its fast swimming ability gives it the alternate name, 'Blue Swimmer Crab'. Crabs are not fussy eaters, these active predators and scavengers eat almost anything. There is an interesting structure of appendages (Maxillipeds) that help the jaws rapidly tear up and manipulate food before being placed in the mouth.

Hairy Pink Hermit Crab (Pagurus sinuatus)

When these crabs outgrow their current shells, they move close to a larger one and crawl out very quickly and into their new home. Unlike most species of crabs, their abdomen is not protected by a carapace, it is soft and usually coiled to fit into empty mollusc shells. Crabs often have one claw larger than the other; in Pagurid species the right claw is larger and the Diogenid have a larger left or both similar in size. Claws on crabs are not only used to source food but also in defence. If there is a shortage of shells the crabs will fight. Pagurus sinatus have very hairy legs which are striped orange, rust and white. These creatures are very shy and will quickly pull their shells over their head if approached. If you see a shell moving along the seabed a good indicator is if it is going slowly it's a mollusc but if it is scuttling along quickly you have yourself a crab. 

Wavy Grubfish (Parapercis haackei)

This alert, aggressive little fish sits up high on its pelvic fins surveying its territory. They are commonly found on sheltered sandy areas and rubble near shallow coastal reefs south west of WA. Males have a black line along their upper lip and the female has two black spots instead. They are often seen in pairs near their burrow which is usually a hole in the sand near a solid object such as a rock or dead shell. They can grow up to 10cm. Males are aggressive towards other fish and vigorously defend their territory. They are particularly fond of eating crustaceans but will take any small fish that moves. This is a very curious fish that will just sit and watch and can make for some good photos. 

Spotted Jelly (Phyllorhiza punctata)

These are a white spotted, brown bell sea jelly with 8 mouth arms that are well developed and branched with tentacles trailing beneath. Instead of a central mouth, they have the mouth arms which have many fine feeding channels that connect to the stomach. Microscopic algae (Zooxanthellae) live in the tissues and cause the brown colouration. Fertilised eggs attach to the mouth arms and remain until they have developed into polyps which bud off as miniature jellies. These jellies do not usually cause painful stings but can irritate sensitive areas of skin such as the face.

West Australian Seahorse

(Hippocampus subelongatus)

These critters (distinguished from other seahorses by brown lines around the snout) live in sheltered bays along the west coast including lower reaches of the Swan River, in sponge gardens, reefs and sea grass beds. They are only found south of Jurien Bay Marine Park to Augusta. Seahorses sway in the current whilst their prehensile tail grabs onto hold fasts such as sea grasses. Their tiny fins can oscillate up to 70 times per second. They have the ability to swim upwards, downwards, forwards, backwards and pivot on the spot. Females lay eggs into the males' pouch on his belly where he incubates them until they hatch into miniature seahorses. Colour varies from white to bright orange, yellow and pink. They also possess the ability to slowly change skin pigmentation to match the colours of the reef around them. They rely on camouflage and their ability to open their mouth very quickly to catch tiny crustaceans as they drift by. Camouflage is also used to avoid predators. 

Tube Anemone (Pachycerianthus species)

You will find these particular creatures (white with purple tipped tentacles) partially submerged in soft sand or mud and if disturbed they can rapidly retract into their tube. They have two sets of tentacles; one short inner circle around the mouth and an outer circle of long, slender tentacles around the edge of the disc. Found throughout southern Australia usually between 5 - 25 meters depth. They are especially common in the Swan River. 

False Tasmanian Blenny

(Parablennius postoculomaculatus)

The Blenny lives in crevices and discarded mollusc shells, cans and beer bottles. Blennies do not have scales but rather tough, slimy skin like a frog and those cute, fluffy antennae of theirs are known as cirri. They use their pectoral and pelvic fins to aid in 'walking'. Many Blennies have an omnivorous diet of algae, coral polyps, small crustaceans and anything else to come their way. When breeding the female is lured into the 'house' by the male where she lays dozens of small, orange eggs along the walls. The male stays to aerate them and keep predators at bay. 

Southern Mantis Shrimp (Poelosquilla laevis)

These Mantis Shrimp can be found occupying sheltered sand and silt up to 40 metres deep. They can grow up to 120mm long and have 6 spines on their last segment of the large claw and three large spines on each side margin of the telson. They are a predatory species and use spiny claws to spear or hammer - like claws to stun prey. Females can either carry or lay their eggs in a burrow. Newly hatched larvae are bottom-dwelling and after one or two molts, the larvae commences a planktonic existence and look quite different to an adult. At this stage it is usually slender with long spine projecting from its head and two spines from near the corners of the carapace. After several months at sea, metamorphoses occurs during a molt and then we have the typical burrowing adult form.

Flathead

These fish bury themselves in the sand or hide under weed where they wait to ambush prey of small fish and crustaceans. They are easily identified by their long snout and large, flat head. Their fine-fringed 'lappet' over the top half of their eye are all unique to the individual fish much like fingerprints are to humans. Common in the river, Flathead can also be found on the more sandier wreck sites and have been seen on the Stragglers Unidentified site and the Centaur.