Mudskippers live in mangrove forests along the tropical coasts of the Indian and Pacific oceans. They inhabit mudflats and tolerate a wide range of salinities. Mudskippers belong to the Goby family – a comparatively recent group of fishes, which first appeared in the fossil record some 58-37 million years ago.
Mudskippers can remain out of water for several days, breathing through specialised chambers in their mouths and gills. When the tide goes out, they skip quickly over the mudflats in search of food, using their sturdy pectoral fins as legs. They are also able to flip themselves forward with their tails, sometimes by as much as a metre. Some species climb up into the tangled roots of mangroves to hunt insects and small crustaceans.
Like many estuarine animals, mudskippers watch over their eggs until they hatch, rather than releasing them into an uncertain environment. The male mudskipper digs a nesting hole in the mud and attracts females to the nest, using a comic courtship display. When a female responds, she attaches her eggs to the wall of the burrow and the male fertilises them.
Shrimpfish, also known as razorfish,(Aeoliscus punctulatus) are found in the Red Sea and off the east coast of Africa from Kenya south to Algoa Bay.
These strange fish swim in an upright vertical position (nose-down). They are perfectly adapted to this lifestyle in that the dorsal fin is situated at the end of their bodies and their tail fin is displaced vertically. They have flattened bodies with bony plates, sharp ventral edges and long snouts.
Shrimpfish are often seen in tightly packed shoals in shallow coastal waters along reef edges and in beds of seagrass.
These fish feed mainly on planktonic crustaceans. In the Aquarium, they are fed on vitamin-enriched brine shrimp as well as zooplankton. They grow to approximately 20cm.
Slender snipefish are distantly related to seahorses and pipefishes. These fish live at depths between 25 and 600m in large shoals.
Tristan five fingers
Tristan five fingers are found only around oceanic islands and seamounts in the south Atlantic- and south Indian Oceans. Juvenile and adult five fingers occur in a wide variety of habitats and in depths from 1.5m to 200m. They can be seen in large shoals in the kelp forests off Tristan da Cunha. They grow to a size of at least 67cm, a weight of 4kg and can reach an age of at least 25 years.
The fish on display were donated to the Aquarium by a rock lobster fishing vessel that collected them as by-catch off Tristan da Cunha Island.
Can you see why they are called five fingers? The structure of the pectoral fins resemble a hand with five fingers.
Found only in southern Africa from central Angola to St Lucia and possibly as far north as Maputo.
Blue stingrays live inshore and are often caught in the surf zone along sandy beaches and estuaries. They are trawled at depths to 109m.
Like other rays, blue stingrays use electro-receptors and highly developed senses of smell and touch to find molluscs, crustaceans, worms and small fishes, which they crush with flattened teeth.
They grow to 75cm and can weigh up to 25kg.
SASSI status: Orange
Like sharks, rays have cartilaginous skeletons. Rays are bottom-dwellers which use camouflage and toxic spines or electric shocks to defend themselves against predators.
Eagle rays are found in the Mediterranean, the eastern Atlantic and around our south coast to Kwa-Zulu Natal. Often caught in trawl nets at depths of up to 95m.
Eagle rays give birth to 4 to 7 live young after a 12-month gestation period. They can live up to 20 years and weigh between 20 to 25kg.
SASSI status: Orange
Biscuit skates occur in the eastern Atlantic Ocean. They can be found in sandy and muddy areas to depths of 700m.
These fish are often caught as by-catch in offshore demersal hake fishery nets. The fishery uses trawl nets which are dragged behind the boat on the ocean floor at depths from 110 - 800 m.
Biscuit skates feed mainly on invertebrates and fish.
SASSI status: Orange
Soles have compressed, asymmetrical bodies with both eyes on the same side of the head.
They are found in temperate and tropical oceans around the world. There are about 13 known species of sole in southern African waters.
- Right-eyed flatfishes – both eyes are found on the right side of the body.
- A sluggish, bottom-dwelling species.
- Camouflage artists – they are sandy coloured and blend into the sand. They also burrow beneath the sand.
Zebra soles have poison glands at the base of each fin ray. If they are attacked, the poison is powerful enough to make the predator release it immediately.
Soles are a popular eating fish.
Soles get their name from solea – which means sandal or sole of the foot.
SASSI status: East coast sole is Orange
Evileye puffers are found in the Indo-West Pacific, mainly along continental shores from Maputo to False Bay.
Round moony (natal moony)
Adult moonies live in rivers, estuaries and harbours whereas juveniles are common in freshwater or estuaries, in seagrass or algae beds. The round moony is less common off the South African south coast than the oval moony.
Both species do well in aquariums.
Grow to a size of between 20 and 25cm.
Cape moony (oval moony)
Moonies are at home in fresh water and salt water. They occur in large shoals in rivers, estuaries, harbours and in the sea from Tanzania to the Breë River (also reported from Madagascar) and are common off the South African south coast. They are active at night and feed on shrimp and small crabs.
They are sometimes called kite fish because of their shape.
Although they prefer the shallow coastal waters of the southern and western Cape, leopard catsharks live at depths up to 250m off the Eastern Cape.