Marine Fauna

Sponges feed through filtering water at a high rate.  Sponges filter the water for small organisms such as algae and bacteria, which then are consumed.

Sponges may reproduce sexually and asexually, and most sponges are both male and female. The ‘male’ sponge would release sperm into the water, which would travel and then enter a ‘female’ sponge. After fertilisation in the sponge, a larva is released into the water. It floats around for a few days and then sticks to a solid underground to begin its growth into an adult sponge.  Asexual reproduction occurs when a small piece of the sponge breaks off but is still able to survive and grow into another sponge. Sponges are also able to repair damage to their bodies.

Forty species of sea firs are found in Maltese waters. These feather-like organisms, which are in fact a colony of several tiny individuals, are difficult to identify on a species-level.

Ranging from a few millimetre to several centimetres in length, the colony filters the surrounding water for other tiny organisms to feed on. Like their close relatives – jellyfishes – sea firs have stinging cells to catch their prey and defend themselves from predators.

The star coral is a protected species, endemic to the Mediterranean. This animal grows in shallow, shady coastal waters where it uses its tentacles to feed on tiny organisms from the surrounding water. Such feeding mode makes this species very sensitive to pollution. Recent research has shown that the polyps (individual specimens) also work together to catch pelagic jellyfish to feed on them.

The cup coral is a shallow water coral that produces a cup-like calcium carbonate external skeleton. It most often occurs in dark, shady areas such as caves, away from light.  This species does not form reefs, but forms large complex colonies.  Members of this species can reproduce both sexually and asexually.

This coral, which lives in shaded habitats, is a solitary coral, and hence does not form colonies.  This species can reproduce both sexually, through interaction of two different solitary corals, or asexually through the break-off and development of a coral part from one single polyp.   They feed on plankton that flows in their vicinity, and colouration of the coral is possibly due to the nutrients extracted from their food.  The maximum estimated lifespan is of 13 years.

This species is very diverse in the habitats it can occur in, ranging from sandy areas close to Posidonia beds to rocky surfaces.  However, it is always found away from direct sunlight.  This species is sensitive to touch, to which it reacts by closing up and pulling the tentacles into the tube. This tube is made of calcium carbonate and serves the worm as housing and protection from predators. It feeds on plankton and particles in the water by using the crown for filter feeding.

This species of marine worm is one of the most delicate species of sea worms.  It grows in large intertwined colonies reaching 15 cm in diameter.  The body rests inside the tube and is an orange colour.  The tubes – which are 1 to 2mm in diameter – are calcareous and act as protective structures.  The tentacles that extend out of the tube are used for feeding.  This species is commonly found on rocky reefs.

The bearded fire worm is very common and is an active predator on reefs, feeding on smaller invertebrates including nudibranchs and sea squirts.  It can grow quite large, reaching 30 cm in length.  Its segmented, slender body can be either a pale golden colour or iridescent red with tufts of white hairs on the edge of each segment on both sides.  If disturbed by touch, the white hairs can easily penetrate the skin, causing severe irritation.

Sea cucumbers are benthic species, meaning species associated with sea bottoms. This species is associated with sandy seabed, but can also be found near seagrass beds and on rocky reefs.

They have thin calcium spines sitting on and within their skin as protection against predators. They are so called “suspension feeders” – preying on smaller animals found in sand or gravel. Sea cucumbers are important for bioturbation of sediments: as they sift through the sediment, trapped oxygen as well as nutrients are released into the water column.

This species is common in the western and central Mediterranean, and can be found in shallow waters from 0 to 30 meter. The species is a herbivore feeding mainly on coralline algae on rocky reefs.  It therefore plays an important role in the ecosystem by controlling algal growth. Fish that prey on these sea urchins include for example sea breams.

This species of sea urchin has poisonous spines that can cause a painful sting.  The spines, which can reach up to 30 cm in length, are mobile and used for locomotion. The Hatpin urchin feeds on algae and is an important species to control algae growth in the reef.

Reproduction is sexual and external.  During the breeding season, it is possible to observe groups of male and female individuals.  Each one then emits its gametes in the form of clouds, in response to pheromone (sexual hormones) emissions. Juvenile growth is 12 mm every year and juvenile appearance is very different from the adult formation. This species is under strict protection.  Thus, this species cannot be damaged or collected.

Despite its name, the colour of this starfish species can vary from purple, to orange or red sometimes with darker purple patches. This species, which can grow in size up to 40 cm, has 5 long arms extending out of a small central disc. If an arm is bitten off, the violet starfish can quickly regenerate it.  Spawning occurs between August and October; however, reproductive cells may be released throughout the entire year for this species. The violet starfish feeds on rock smaller encrusting organisms, crustaceans, small fish, detritus and other organic material. This species is strictly protected. Therefore, this species cannot be collected or damaged in any way.

This species of hermit crabs appears in bright orange/red colours. As the names indicates, the hermit crab uses shells of other species as cover and home. While growing, hermit crabs have to change shells several times during their lifespan, leading them to spend much time searching for new ones.  Empty shells should therefore be left in the sea and not be collected.

This shrimp is a global species, which means that it can be found in different parts of the world. Its lifespan ranges from 2 to 5 years. The difference in lifespan can be due to the variations in water temperature, with individuals in warm waters having shorter lifespans. Sexual maturity is acquired early in their life cycle, with males reaching sexual maturity in the first 7 months and females within the first 10 months. Females are generally larger and heavier than males. Members of this species feed on edible detritus and Opossum shrimps. The common shrimp reproduces sexually, with development in the female being the controlling factor as to when this happens. Egg development is affected by water temperature, with slower development rates in cold waters than warmer ones.

These small crustaceans are commonly encountered in shallow waters. They are easy to identify due to their intense yellow to orange coloration with white claws and antennae. Individuals of this species move very slowly, often being described as undertaking majestic movements, even in the face of danger.  To acquire food, this species scavenges and are often seen acting as fish cleaners, eating material off fish’s bodies. Golden coral shrimps have separate sexes thus are either male or female. Prior to reproduction, a courtship ritual is common, mainly involving smell and touch.

The spiny lobster may vary in colour from typically orange colouration to brown, sandy or purple colours. Males are known to be sexually mature when their hard shell is roughly 8.5cm long, while females have a carapace between 7 and 8 cm long at maturity.

Lobster typically feed on echinoderms, small gastropods and bivalves, microalgae, shrimp larvae, bryozoans, annelids.

They can very clearly sense the presence of their predator, the common octopus, by detecting the smell of this species.

This species can only be found in the Mediterranean and is the largest bivalve in this Sea. Its shell can reach up to 1 m in height. It occurs in sandy coastal areas, usually associated with Posidonia oceanica meadows and can live at depths of 60 m. Due to the rapid decline of this species because of different pressures, including collection for ornamental purposes, anchoring and pollution, this species is strictly protected. If encountered, this species should not be damaged, touched or detached from the substratum to which it is attached.

This species is a large predatory snail that feeds on starfish. Its beautiful shell has been traded by humans for many years, contributing to a population decrease. Nowadays sightings are rare. This species is strictly protected and should not be touched, picked or disturbed in any way.

The shells of the Mediterranean cowrie are brown (sometimes reddish) in colour and with two white bands on its dorsal surface alternating with the darker, wide bands. They can be found on rocky shores, feeding on sponges, mainly during the night. This is because the species is not well adapted for high light levels and thus during the day are usually found in shaded, dark places. The Mediterranean cowrie is one of national interest and is placed under strict protection. Shells should not be picked and the general habitat should not be damaged.

The dotted sea slug is commonly found in dark shaded areas such as cave walls and ceilings. It occurs down to 40 m depths and is commonly associated with the sponges on which it feeds exclusively. The distinct coloration is a defence against potential predators.

This Mediterranean nudibranch is characterised by a blue coloration over its entire body, with dark blue, short sensory structures with white tips on its head. These structures provide the organism with information relating to its surroundings while allowing it to taste and smell too. The blue, tube-like structure on the other end are its gills.

This species feeds on a range of sponges, and can be found at depths of up to 50 to 60 meters.

Specimen of the red papillae dorid are relatively small with a maximum of 10 mm in length. The red papillae dorid has a white body with a yellow border enclosing and thus marking the backside for this animal. Long, thick, hair-like structures referred to as papillae occur within the yellow border, and are of a bright red coloration. Two sensory structures, white in colour, are present at the tip of the organism’s head. As in other nudibranchs, the gills are exposed, located at the posterior end of the organism.  Organisms are hermaphrodites, and reproduction occurs at the beginning of summer.

Sepia spp. commonly known as cuttlefish are masters of camouflage, changing their skin coloration and texture to escape from predators or communicate with other cuttlefish. Despite this, cuttlefish are actually colour-blind. These organisms are hard to spot and are very fast swimmers, escaping danger efficiently. Spawning can happen all year around. The male passes its sperm to the female, which then produced fertilised, oval eggs that are deposited on the seabed. Similar to their close relatives, octopuses, they have a relatively short life span of 1 to 2 years.

Octopuses are found in a variety of habitats, such as rocks, reefs, and seagrass beds. They are very intelligent and have problem-solving abilities. They can also change colour, skin texture and shape instantaneously, and regenerate missing arms at will.

Females tend to reach maturity during months April to August with approximately 500-gram weight, while male reach it earlier at about 300 gram. Octopus only reproduce once. The females guards the fertilised eggs until they hatch and then dies. Their lifespan is therefore very short – around 12 to 15 months. This implies that such species is sensitive to fishing pressure.

Striped blenny adults – which are around 8 cm long – can be found in shallow water on rocks and pebbles. They feed on a mixture of algae, small organisms and organic matter. Males inhabit narrow holes; they court by nodding, jumping out of hole and back again and swimming in a vertical position. Females lay eggs in the males’ resident holes; the eggs are attached to the substrate by an adhesive pad or pedestal. The Male then protects and defend the eggs until they hatch.

This wrasse is one of the most ornately decorated fish that one can encounter in the Mediterranean sea.  It can grow up to 20 cm and has various colorations throughout its growing phase. This species lives in shallow, warm waters close to the coast. It feeds on small worms and crustaceans, being an active predator during the day while sleeping at night, typically buried in the sand. It forms large groups during spawning, when fish release fertilised eggs into the water column. It is very easy to distinguish between males and females: both sexes are characterised by beautiful colouring patterns, but only females have wide, distinctive stripes across their entire body. Interestingly all ornate wrasses are born female and are able to change their sex to male, when the need arises.

Groupers are a commonly found in rocky reefs and close proximity to caves in Malta. Depending on their size, they feed on different marine organisms. Smaller grouper prefer crustaceans. When growing they then switch their preference to cephalopods (squids, octopus, cuttlefish). Larger specimen prefer smaller fish.  Groupers are known to live for over 50 years.

In Malta, it is not allowed to catch the dusky grouper if smaller than 45 cm in length. This is in order to allow the grouper to reproduce. This grouper species undergoes a transition from female to male once a certain size is reached (approx. 80 cm). During the reproductive period, males establish territories, which they defend aggressively against other male dusky groupers and other fishes. One male will mate with several females during this period. In the Mediterranean, spawning happens around June to August, and hence groupers should especially not be disturbed during this time.

The characteristic feature for the flying gurnard is their enlarged fins. These are displayed when the organism perceives danger. They also act as “legs” allowing the fish to “walk” over the sediment in search for food, mainly crustaceans and other small invertebrates. The mating season of flying gurnards is in summer, from May to July. Prior to mating, male and female “dance” together by swimming in circles behind each other and occasionally flapping their fins on the sand.

The painted comber can instantly be recognised due to its unique coloration with distinct markings around the face and broad bands on its body. The facial markings and bands are a bright orange-red colour that may appear dark brown at night, and are wider and darker towards the tail. This species occurs in shallow waters particularly rocky reefs filled with holes, which provide both protection and food, such as small crustaceans, fishes and worms. This species can also be found within Posidonia beds. Spawning occurs from January to September with a peak in June.

Parrot fish specimens are more common on the eastern coast of the archipelago than on the western coast. This species shows great variance in morphology between males and females: males have a blue-grey shiny colouration while females are overall a bright orange-red. This species of fish is found in depths which do not exceed 50 m and can be seen feeding on algae that grows on rocks or corals and small invertebrates, during the day. These fish play a key role in controlling algal growth.

The red scorpion fish gets its name from the small spiny rays on its head that resemble scorpion spines and are poisonous. These fish are associated with rocky coastal habitats, but can also be found at depths of up to 700 m. The small red scorpion fish usually feeds on crustaceans and small fishes. Males and females form reproductive aggregations, but otherwise tend to live solitary lives.

This curious species has a large head, which is rounded. During the summer months, it is encountered at depths between 1 and 20 m, while in winter it migrates to greater depths. This species quickly flees danger or disturbance by burrowing itself into the soft sediment.

This species of eel is known for burrowing in sand or mud, most typically in fine sand. This species can reach a 1 m in length. As the name implies, this species lacks any fins.

The European finless eel occurs at depths of 1 to 85 m.

Seahorses go through life having one single mate, and reproduction is different to many other animals. They undergo a complex mating-dance, which occurs every morning for a number of days, typically with tails intertwined. When ready, the female deposits her eggs through a tubular protrusion into the male’s brood pouch. Shortly after, the male gives birth to numerous (can be thousands) of fully independent offspring, by which time the female has her eggs ready for another reproductive cycle, which occurs immediately after. Seahorses do not provide their young with parental care, which is why they produce a large number of offspring.

Sea horses feed on small shrimp and other tiny plank-tonic crustacean, picking at them with them long snouts, sucking them into their mouth.

This species prefers seagrass habitats and often has algal bits growing on their body, which enhances their camouflage capability. These species are very delicate and are strictly protected; they should not be touched, picked, chased or hurt in any way.

Moray eels have an elongated, snake-like bodies and swim in the water through undulations that travel throughout their body. The Mediterranean moray eel can reach a length of 1.5 m.  Males reach maturity at approximately 80 cm long and females at approximately 78 cm long.

Morays are often found hiding in small crevices and caves during the day. They usually come out at dusk or dawn to hunt for smaller marine organisms. Their diet varies in relation to the depth at which they live and includes octopus, crustaceans and fish.

Common eagle rays can be found in shallow bays, but also occur offshore at depths below 500 m.

Eagle rays are often encountered in groups, searching muddy or sandy seabed for crustaceans, molluscs and small fish.

Depending on the region, the maximum length, size at maturity and reproduction phase can vary. For the Mediterranean, this ray reaches about 1.5 m in disc width and 2.6 m total length, with females being mature at about 60 cm disc width and males at 40 cm. After mating, the females have a gestation period of about 6-8 months, after which they give birth to 3-7 pups that hatch inside their uterus from egg capsules before “being born” into the sea.

Reproduction takes place between September and February.

Cetaceans are one of the most distinctive and highly specialised orders of marine mammals that include whales, dolphins and porpoises. Sightings of different species of whales and dolphins were recorded in the past years in the Maltese Islands; however, the species which are regularly sighted in Maltese waters are the bottlenose dolphin, the common dolphin, and the striped dolphin.

These animals are migratory, passing through Maltese waters particularly during summer months, when they are often sighted from boats, and are typically observed in groups of several individuals, referred to as pods. As is the case for all marine mammals in the Mediterranean, these species are strictly protected. They should not be chased or disturbed when encountered.

These species are top-level predators, meaning that they play a key role in maintaining balance in the ecosystem. In fact, there are several EU and regional obligations targeting the protection of these species. Specifically, Malta is a member of the Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and contiguous Atlantic area (ACCOBAMS), which is a legal conservation tool with the aim to reduce threats to cetaceans by carrying out research studies and improving current knowledge on these animals. Given the migratory characteristics of these species, the Agreement was established under the auspices of the Bonn Convention (UNEP/CMS).

Malta has also designated a number of marine protected areas in the Natura 2000 network  in view of their importance for the bottlenose dolphin and the loggerhead turtle.

The loggerhead sea turtle is one of the five species of turtles that occur in Mediterranean waters. This species, unlike the other four, occurs frequently in Maltese waters. There have also been occasional sightings of the leatherback turtle in recent years.

Loggerhead turtles feed on a variety of crustaceans, cephalopods and smaller fish. The loggerhead turtle can take between 23 to 29 years to reach maturity, and can live up to 45 years. To undertake breeding, loggerhead males and females undergo migrations between feeding grounds and nesting grounds with the migration intervals for females being longer than those undertaken by males.

This species is protected across the Mediterranean. Three marine protected area have been designated in Maltese waters based on the presence of loggerhead turtles and bottle-nose dolphins.

The Maltese archipelago attracts birds crossing between the two continents in their spring and autumn journeys. Malta thus hosts internationally important bird species throughout their migration and breeding seasons. Among these are three species of seabirds for which Malta is deemed to be an internationally important breeding location: the Scopoli’s Shearwater (Calonectris diomedea); Yelkouan Shearwater (Puffinus yelkouan); and the Mediterranean Storm Petrel (Hydrobates pelagicus). Aggregations of seabird species are regularly observed on coastal waters during spring and autumn migrations or during winter.

Coastal cliffs and screes, which predominate along the Southwestern coast of the Maltese Islands, provide shelter and a breeding habitat. Scopoli’s Shearwater breed along the western cliffs of Malta and Gozo with several other less extensive colonies on Filfla, the east cliffs of Comino and Rdum tal-Madonna. A majority of colonies of Yelkouan Shearwater span small sections of cliffs and are focused in the north of Malta, south of Gozo, Comino and Cominotto. The Mediterranean Storm Petrel is a highly localised breeder in Malta, with the island of Filfla being the stronghold of this species in the Maltese Islands. Several smaller colonies exist in sea-caves at Għarb, Ta’ Ċenċ and Rdum tal-Madonna.

These three species are ‘pelagic-feeding birds’, which means that they spend a significant part of their life on the open ocean, only returning to land to nest and breed. In total, eight marine areas within Malta’s Fisheries Management Zone have been designated as Special Protected Areas in view of their importance for these protected seabirds during their breeding season.