| Finless sole | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Pleuronectiformes |
| Family: | Soleidae |
| Genus: | Pardachirus |
| Species: | P. marmoratus |
| Binomial name | |
| Pardachirus marmoratus (Lacépède, 1802) | |
| Synonyms | |
| |
Pardachirus marmoratus, the finless sole, speckled sole or Red Sea Moses sole, [1] is a species of flatfish native to the western Indian Ocean.
The adult finless sole is bilaterally symmetrical and as they mature their left eye migrates on to the right side of the head. The highly compressed body is convex on the eyed side and flat on the blind side. The rounded caudal fin is not attached to either the dorsal or cloacal fin. It is variable in colour frequently whitish, pale brown to pale grey with a scattering of irregular dark brown ring shape markings and many dark brown spots on the head, body, and fins. Along the lateral line, there are normally two brown dots containing yellow flecks. [2]
This species occurs in the western Indian Ocean from the Red Sea to Sri Lanka and along the east coast of Africa to Durban. [1] It is found in shallow, coastal waters where the seabed consists of sand or mud, [1] often near coral reefs, [2] and they feed mainly on benthic invertebrates. It is caught for consumption, despite the poison it exudes and is marketed fresh. [1] They often spend the day buried in the sand with only its eyes and nostrils visible. [2]
The finless sole secretes a milky ichthyotoxin [3] from the base of its dorsal and cloacal fins. This secretion contains pardaxin, a lipophillic peptide that causes severe plasma membrane disruption resulting in cell leakage. The pardaxin containing secretion is used as a defensive mechanism against predators including sharks. Pardaxin is irritating to predator fish, particularly affecting the sensitive gills. Eugenie Clark conducted much of the early work on the species. [4]
There is much biotechnological interest in pardaxin, early interest focused on potential shark repellent applications while newer research focuses on antimicrobial and neurotoxic potential of pardaxin and its analogues. [4] One toxin produced, pardaxin-1, does have unusual shark repellent and surfactant properties. It created voltage-dependent, ion-permeable channels in membranes and at high concentration it causes lysis in cell membranes. This toxin has been demonstrated to be 5-10 times more toxic, cytolytic and active in the formation of pores in cell membranes than the other toxin exuded, pardaxin-2. [5]
Mimic Octopuses have been known to mimic them. [6]
Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved venom apparatus, such as fangs or a stinger, in a process called envenomation. Venom is often distinguished from poison, which is a toxin that is passively delivered by being ingested, inhaled, or absorbed through the skin, and toxungen, which is actively transferred to the external surface of another animal via a physical delivery mechanism.
Pardaxin is a peptide produced by the Red Sea sole and the Pacific Peacock sole that is used as a shark repellent. It causes lysis of mammalian and bacterial cells, similar to melittin.
Tetrodotoxin (TTX) is a potent neurotoxin. Its name derives from Tetraodontiformes, an order that includes pufferfish, porcupinefish, ocean sunfish, and triggerfish; several of these species carry the toxin. Although tetrodotoxin was discovered in these fish, it is found in several other animals. It is also produced by certain infectious or symbiotic bacteria like Pseudoalteromonas, Pseudomonas, and Vibrio as well as other species found in symbiotic relationships with animals and plants.
The South Australian cobbler, better known as the soldier but also known as the cobbler, devilfish or soldierfish, is a species of marine ray-finned fish, a waspfish, belonging to the subfamily Tetraroginae which is classified within the family Scorpaenidae, the scorpionfishes and their relatives. It is endemic to southern Australia. It is the only species in the monotypic genus Gymnapistes.
Anti-predator adaptations are mechanisms developed through evolution that assist prey organisms in their constant struggle against predators. Throughout the animal kingdom, adaptations have evolved for every stage of this struggle, namely by avoiding detection, warding off attack, fighting back, or escaping when caught.
A shark repellent is any method of driving sharks away from an area. Shark repellents are a category of animal repellents. Shark repellent technologies include magnetic shark repellent, electropositive shark repellents, electrical repellents, and semiochemicals. Shark repellents can be used to protect people from sharks by driving the sharks away from areas where they are likely to harm human beings. In other applications, they can be used to keep sharks away from areas they may be a danger to themselves due to human activity. In this case, the shark repellent serves as a shark conservation method. There are some naturally occurring shark repellents; modern artificial shark repellents date to at least the 1940s, with the United States Navy using them in the Pacific Ocean theater of World War II.
Eugenie Clark, popularly known as The Shark Lady, was an American ichthyologist known for both her research on shark behavior and her study of fish in the order Tetraodontiformes. Clark was a pioneer in the field of scuba diving for research purposes. In addition to being regarded as an authority in marine biology, Clark was popularly recognized and used her fame to promote marine conservation.
Venomous fish are species of fish which produce strong mixtures of toxins harmful to humans which they deliberately deliver by means of a bite, sting, or stab, resulting in an envenomation. As a contrast, poisonous fish also produce a strong toxin, but they do not bite, sting, or stab to deliver the toxin, instead being poisonous to eat because the human digestive system does not destroy the toxin they contain in their bodies. Venomous fish do not necessarily cause poisoning if they are eaten, as the digestive system often destroys the venom.
The Australian swellshark or draughtboard shark, is a species of catshark, and part of the family Scyliorhinidae, endemic to southern Australia. This bottom-dwelling species can be found on the continental shelf down to a depth of 220 m (720 ft). Usually measuring 1 m long, it is a stout-bodied, broad-headed shark with a short tail and a first dorsal fin much larger than the second. It can be identified by its variegated dorsal coloration of brown or grey patches and numerous spots.
The coral catshark is a species of catshark in the family Scyliorhinidae. It is common on shallow coral reefs across the Indo-West Pacific, from Pakistan to New Guinea. Reaching up to 70 cm (28 in) in length, the coral catshark has an extremely slender body, a short head and tail, and two dorsal fins that are angled backwards. It can be identified by the numerous black and white spots on its back, sides, and fins, which often merge to form horizontal bars. Furthermore, adult males have distinctively long and thin claspers.
The greater weever is a benthic and demersal venomous marine fish of the family Trachinidae. The greater weever is widely distributed along the eastern Atlantic coastline from Norway to Morocco, extending to the Mediterranean, Aegean and Black Seas. Trachinus draco has been shown to occur in depths ranging from shallow water up to -150 meters where it inhabits mostly muddy or sandy grounds. Trachinus draco is mostly and notoriously known for its venomous spines that can inflict serious injuries on humans through accidental stinging. Because of these spines and its potent venom it is classified as one of the most venomous fishes in the Mediterranean. The name “weever” is thought to originate from the Anglo-Saxon word “wivre” which translates as “viper”.
The velvet belly lanternshark is a species of dogfish shark in the family Etmopteridae. One of the most common deepwater sharks in the northeastern Atlantic Ocean, the velvet belly is found from Iceland and Norway to Gabon and South Africa at a depth of 20–2,490 m (66–8,169 ft). A small shark generally no more than 45 cm (18 in) long, the velvet belly is so named because its black underside is abruptly distinct from the brown coloration on the rest of its body. The body of this species is fairly stout, with a moderately long snout and tail, and very small gill slits. Like other lanternsharks, the velvet belly is bioluminescent, with light-emitting photophores forming a species-specific pattern over its flanks and abdomen. The ventral photophores are thought to function in counter-illumination, which camouflages the shark against predators and prey. The bioluminescent flank markings may play a role in intraspecific communication.
The tiger catshark is a species of catshark, belonging to the family Scyliorhinidae. It is found over sandy areas and near reef peripheries off South Africa and perhaps Mozambique, from close to shore to usually no deeper than 100 m (330 ft). Reaching a length of 50 cm (20 in), this small, slim shark has a broad, flattened head with an upturned snout tip. It can additionally be identified by its dorsal colour pattern of ten dark brown saddles on a yellowish brown background.
Samuel H. Gruber was a shark biologist and founder of the American Elasmobranch Society. He was a professor at the University of Miami's Rosenstiel School for Marine and Atmospheric Science and the founder of the Bimini Biological Field Station Foundation.
The finless sleeper ray is a species of electric ray in the family Narkidae, and the sole member of its genus. It is found over the continental shelf of Southeast Asia from the eastern Andaman Sea to Vietnam and Borneo. Typically growing no more than 15 cm (5.9 in) long, it may be the smallest cartilaginous fish. The finless sleeper ray is the only electric ray that lacks dorsal fins. It has an oval pectoral fin disc that varies from longer than wide to wider than long, depending on age, and a short, robust tail that terminates in a short, deep caudal fin. The trailing margins of its pelvic fins are sexually dimorphic, being more concave in males.
Coral reef fish are fish which live amongst or in close relation to coral reefs. Coral reefs form complex ecosystems with tremendous biodiversity. Among the myriad inhabitants, the fish stand out as colourful and interesting to watch. Hundreds of species can exist in a small area of a healthy reef, many of them hidden or well camouflaged. Reef fish have developed many ingenious specialisations adapted to survival on the reefs.
Scorpaena guttata is a species of fish in the scorpionfish family known by the common name California scorpionfish. It is native to the eastern Pacific Ocean, where it can be found along the coast of California and Baja California. Its distribution extends from around Santa Cruz, California, to Punta Abreojos in Baja California Sur, and out to Guadalupe Island. It is also found in the Gulf of California. Another common name is spotted scorpionfish.
Dinogunellins are unusual toxic phospholipids found in the roe of some fishes, and is one of the best studied ichthyotoxin. These phospholipids could be found as a complex with non-toxic proteins like in the cabezon toxin or in the lipostichaerin.
Grammistins are peptide toxins synthesised by glands in the skin of soapfishes of the tribes Grammistini and Diploprionini which are both classified within the grouper subfamily Epinephelinae, a part of the family Serranidae. Grammistin has a hemolytic and ichthyotoxic action. The grammistins have secondary structures and biological effects comparable to other classes of peptide toxins, melittin from the bee stings and pardaxins which are secreted in the skin of two sole species. A similar toxin has been found to be secreted in the skin of some clingfishes.