Redspotted catshark
The redspotted catshark, Schroederichthys chilensis, also known as the Chilean catshark, is a species of catshark
Catsharks are ground sharks of the family Scyliorhinidae, with over 150 known species. While they are generally known as catsharks, many species are commonly called dogfish....

 commonly found in the coastal waters of the southeastern Pacific, from central Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

 to southern Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

. They are typically found in the rocky sublittoral areas at the edge of the continental shelf
Continental shelf
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...

, in waters down to 100 m in depth. They spend the spring, summer, and fall in rocky subtidal areas, but winter in deeper offshore waters due to the strong currents at this time.

Physical description

Redspotted catsharks range in length from 30 to 66 cm, although these sizes are taken from captured sharks, and it is believed that they may grow larger than this.

Their bodies are elongate and sleek, typical of the catshark family. Their dorsal
Dorsum (biology)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...

 side is a dark reddish brown with dark saddle patterns on their side. Their ventral sides are a creamy white with reddish spots. Redspotted catsharks have two dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...

s, with the first dorsal axil over the pelvic region. Their dorsal fins do not have spines, and their tails have no upward bend.

Redspotted catsharks have multicuspid teeth, however males typically have longer teeth with fewer cusps. This is believed to aid in courtship
Courtship is the period in a couple's relationship which precedes their engagement and marriage, or establishment of an agreed relationship of a more enduring kind. In courtship, a couple get to know each other and decide if there will be an engagement or other such agreement...



Redspotted catsharks are solitary, nocturnal creatures. They stay in caves and crevices during the day and emerge at night to feed. They are migratory
Fish migration
Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres...

, however they live most of the year near the edge of the continental shelf.

Communication specific to the redspotted catshark is unknown. However, as with most other sharks, including other members of the family Scyliorhinidae, it is believed that they have a well-developed sense of smell, and that they are electroreceptive, which allows them to detect electricity emitted by other animals, and may also allow them to detect magnetic fields, which aids in navigation
Navigation is the process of monitoring and controlling the movement of a craft or vehicle from one place to another. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks...


Food habits and predation

Redspotted catsharks feed on organisms that dwell on the rocky bottom near the continental shelf
Continental shelf
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...

. Their primary food sources are various species of crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...

s and rock shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...

. They have also been known to eat fishes, algal material
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

, and various polychaete
The Polychaeta or polychaetes are a class of annelid worms, generally marine. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. Indeed, polychaetes are sometimes referred to as bristle worms. More than 10,000...


Redspotted catsharks are an important predator within their ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

. They have a large influence on commercially fished benthic organisms that dwell in the rocky near-shore areas.

Redspotted catsharks are host to trypanosomes
Trypanosoma is a genus of kinetoplastids , a monophyletic group of unicellular parasitic flagellate protozoa. The name is derived from the Greek trypano and soma because of their corkscrew-like motion. All trypanosomes are heteroxenous and are transmitted via a vector...

, parasites
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...

 that are passed into the catsharks' bloodstream through leech
Leeches are segmented worms that belong to the phylum Annelida and comprise the subclass Hirudinea. Like other oligochaetes such as earthworms, leeches share a clitellum and are hermaphrodites. Nevertheless, they differ from other oligochaetes in significant ways...


There are no known predators to the catshark, although juveniles typically spend their early life in the deeper offshore waters. This is believed to be to avoid predators, although what those predators are is unknown.


Redspotted catsharks are oviparous. Breeding occurs in individuals in an annual cycle. However, they mate seasonally, typically in spring and winter, though females have occasionally been shown to have egg capsules in the summer. They are polygynandrous and while the male fertilizes the female's eggs he typically performs what is called a "courtship ritual" that consists of the male biting the female.

Redspotted catsharks are born from encapsulated eggs that are fertilized and released into the water. There are typically two eggs in each capsule, which can also be called a mermaid's purse
Mermaid's purse
An egg case or egg capsule, colloquially known as a mermaid's purse or devil's purse, is a casing that surrounds the fertilized eggs of some sharks, skates, and chimaeras. They are among the common objects which are washed up by the sea. They are made of collagen protein strands...

. Embryos feed on the yolk of the egg until they hatch. Once these eggs hatch the sharks appear to be miniature versions of adults, however, the sharks grow rapidly. It is believed that juveniles swim into deeper waters in order to avoid predation in the sublittoral zone that they return to when they are adults. Therefore, there is a spatial segregation between adult and juvenile populations.

Conservation status and economic impact

Redspotted catsharks are not listed as endangered on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...

, the U.S. Federal List, or the CITES list. They are not known to be a vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...

 or threatened species.

Redspotted catsharks have a negative economic impact on humans. They feed heavily on near shore benthic crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...

s. This is a detriment to commercial fisherman because crustaceans in this area have a large economic importance. Catsharks are also a frequent bycatch
The term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...

 of nearshore fishing trawlers, which, while not economically significant, can cause damage to nets as well as time lost in removing the bycatch from the viable catch.

External links

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