Redspotted catshark

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Redspotted catshark
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Subdivision: Selachimorpha
Order: Carcharhiniformes
Family: Scyliorhinidae
Genus: Schroederichthys
Species:
S. chilensis
Binomial name
Schroederichthys chilensis
(Guichenot, 1848)
Schroederichthys chilensis distmap.png

The redspotted catshark (Schroederichthys chilensis), also known as the Chilean catshark, is a species of catshark commonly found in the coastal waters of the southeastern Pacific, from central Peru to southern Chile. They are typically found in the rocky sublittoral areas at the edge of the continental shelf, 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 that time of year.

Contents

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 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 fins, 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 biting.

Behavior

Redspotted catsharks are solitary, nocturnal creatures. They stay in caves and crevices during the day and emerge at night to feed. They are migratory. 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.

Redspotted catsharks are host to trypanosomes, parasites that are passed into the catsharks' bloodstream through leeches.

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. Breeding and oviposition seem to occur throughout the year in an annual cycle. The paucity of ovigerous females during fall probably indicates that eggs were laid during summer, when massive depositions of egg-cases occurred on fronds of the subtidal brown kelp 'Lessonia trabeculata'. [2] [3]

Feeding

Redspotted catsharks feed on organisms that dwell on the rocky bottom near the continental shelf. Their primary food sources are various species of crabs and the rhynchocinetid rock shrimp Rhynchocinetes typus. [4] Redspotted catsharks are an important predator within their ecosystem. They have a large influence on commercially fished benthic organisms that dwell in the rocky near-shore areas.

The research of presence/absence effect of kelp Lessonia trabeculata on the isotopic niche of redspotted catshark present that males were characterized by higher trophic position and enriched carbon sources compared to females in locations where kelp was present. In contrast, males and females were characterized by similar isotopic niche in absence of kelp. These differences are most probably an effect of higher prey diversity associated with microhabitats generated by kelp forests that allow sexual segregation of isotopic niche. Therefore, extensive kelp harvest may cause significant effects in isotopic niche and nutritional status of adult redspotted catshark and may negatively affect its populations. [5]

Reproduction

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. 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, the U.S. Federal List, or the CITES list. They are not known to be a vulnerable or threatened species.

Redspotted catsharks have a negative economic impact on humans. They feed heavily on near shore benthic crustaceans. This is a detriment to commercial fisherman because crustaceans in this area have a large economic importance. Catsharks are also a frequent bycatch 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.

Related Research Articles

<span class="mw-page-title-main">Catshark</span> Family of fishes

Catsharks are ground sharks of the family Scyliorhinidae. They are the largest family of sharks with around 160 species placed in 17 genera. Although they are generally known as catsharks, some species can also be called dogfish due to previous naming. However, a dogfish may generally be distinguished from a catshark as catsharks lay eggs while dogfish have live young. Like most bottom feeders, catsharks feed on benthic invertebrates and smaller fish. They are not harmful to humans. The family is paraphyletic, containing several distinct lineages that do not form a monophyletic group.

<span class="mw-page-title-main">Chain catshark</span> Species of shark

The chain catshark or chain dogfish is a small, reticulated catshark that is biofluorescent. The species is common in the Northwest Atlantic, Gulf of Mexico, and Caribbean. It is harmless and rarely encountered by humans. It has very similar reproductive traits to the small-spotted catshark.

<span class="mw-page-title-main">Brown catshark</span> Species of shark

The brown catshark is commonly found in the Pacific Ocean, ranging from the northern Pacific waters off the coast of British Columbia and south to the Baja California peninsula in Mexico. They may live as far south as Ecuador and Peru. Brown catsharks are deep-water sharks that live on the outer continental shelf and the upper slope. They have been known to live at depths ranging from 30 to 650 m and live on the bottom, usually in muddy or sandy areas. The brown catshark, when originally described, was called Catulus brunneus.

<span class="mw-page-title-main">False catshark</span> Species of shark

The false catshark or sofa shark is a species of ground shark in the family Pseudotriakidae, and the sole member of its genus. It has a worldwide distribution, and has most commonly been recorded close to the bottom over continental and insular slopes, at depths of 500–1,400 m (1,600–4,600 ft). Reaching 3.0 m (9.8 ft) in length, this heavy-bodied shark can be readily identified by its elongated, keel-like first dorsal fin. It has long, narrow eyes and a large mouth filled with numerous tiny teeth. It is usually dark brown in color, though a few are light gray.

<span class="mw-page-title-main">Lollipop catshark</span> Species of shark

The lollipop catshark is a little-known species of deep sea catshark, belonging to the family Scyliorhinidae, and the only described member of its genus. A diminutive, bottom-dwelling shark of the outer continental shelf and upper continental slope, this species can be readily identified by its tadpole-like shape with a greatly expanded, rounded head and narrow body. The large head houses expanded gills, which are thought to be an adaptation for hypoxic conditions. This shark preys on crustaceans and fishes. Reproduction is aplacental viviparous, with females retaining egg cases internally two at a time until they hatch. There is no fishery interest in this species.

<span class="mw-page-title-main">Pyjama shark</span> Species of shark

The pyjama shark or striped catshark is a species of catshark, and part of the family Scyliorhinidae, endemic to the coastal waters of South Africa. This abundant, bottom-dwelling species can be found from the intertidal zone to a depth of around 100 m (330 ft), particularly over rocky reefs and kelp beds. With a series of thick, parallel, dark stripes running along its stout body, the pyjama shark has an unmistakable appearance. It is additionally characterized by a short head and snout with a pair of slender barbels that do not reach the mouth, and two dorsal fins that are placed far back on the body. It can grow up to a length of 1.1 m (3.6 ft) long.

<span class="mw-page-title-main">Leopard catshark</span> Species of shark

The leopard catshark is a species of catshark, and part of the family Scyliorhinidae, endemic to the coastal waters of South Africa. Abundant in inshore waters under 20 m (66 ft) deep, this bottom-dweller favors rocky reefs, kelp beds, and sandy flats. Growing to a length of 84 cm (33 in), the leopard catshark has a stout body with two dorsal fins placed well back, and a short head and tail. It is extremely variable in color and pattern, with individuals ranging from almost white to black and covered by diverse patterns of black spots, blotches, rosettes, and/or lines. The color pattern changes with age and some forms seem to be location-specific, suggesting the presence of multiple distinct, local populations. In the past, some of the more distinct color forms have been described as different species.

<span class="mw-page-title-main">Izak catshark</span> Species of catshark, of the family Scyliorhinidae

The Izak catshark or simply Izak is a species of catshark, belonging to the family Scyliorhinidae, common off the coasts of South Africa and southern Namibia. It typically inhabits the outer continental shelf at depths of 100–300 m (330–980 ft), with the males found deeper than the females and juveniles. The Izak catshark has a short, wide, flattened head and a robust body tapering to a long, slender tail. It can be identified by its ornate color pattern of dark brown spots or reticulations and blotches on a light yellowish background, as well as by the enlarged dermal denticles over its pectoral fins and along its dorsal midline from the snout to the second dorsal fin. This species reaches 69 cm (27 in) in length, with the males larger than females.

<span class="mw-page-title-main">Speckled smooth-hound</span> Species of shark

The speckled smooth-hound is a houndshark of the family Triakidae. It is found on the continental shelf of the eastern Pacific, between latitudes 0° and 54° S, at depths between 16 and 50 m. It can reach a length of 130 cm (51 in). Collectively with certain other species of shark, it is known as "tollo".

<span class="mw-page-title-main">Narrowmouthed catshark</span> Species of shark

The narrowmouthed catshark is a catshark of the family Scyliorhinidae, found from central Chile around the Straits of Magellan, to Argentina between latitudes 23° S and 56° S, at depths down to about 180 m (600 ft) in the Atlantic Ocean and about 360 m (1,200 ft) in the Pacific. It can grow to a length of up to 70 cm (28 in). The reproduction of this catshark is oviparous.

<span class="mw-page-title-main">Narrowtail catshark</span> Species of shark

The narrowtail catshark is a catshark of the family Scyliorhinidae, found off the coasts of Honduras and Nicaragua, between latitudes 18° N and 10° N, at depths between 190 and 410 m. It can grow up to a length of 35 cm (14 in). The reproduction of this catshark is oviparous.

The lizard catshark is a small shark species of the catshark family, Scyliorhinidae, found off the coast of southern Brazil on the upper continental shelf at depths of between 250 and 500 metres.

<span class="mw-page-title-main">Slender catshark</span> Species of shark

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<span class="mw-page-title-main">Puffadder shyshark</span> Species of shark

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<span class="mw-page-title-main">Dwarf catshark</span> Species of shark

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<span class="mw-page-title-main">Quagga catshark</span> Species of fish

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<span class="mw-page-title-main">Cloudy catshark</span> Species of shark

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Medialuna ancietae is a species of sea chub native to the Pacific coast of South America where it inhabits the giant kelp forests. It is known locally as acha, mero del sur or chino.

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References

  1. Dulvy, N.K.; Acuña, E.; Bustamante, C.; Herman, K.; Velez-Zuazo, X. (2020). "Schroederichthys chilensis". IUCN Red List of Threatened Species . 2020: e.T44585A124433964. doi: 10.2305/IUCN.UK.2020-3.RLTS.T44585A124433964.en . Retrieved 19 November 2021.
  2. Fariña, Jose; Ojeda, Patricio (1993). "Abundance, activity, and trophic patterns of the redspotted catshark, Schroederichthys chilensis, on the pacific temperate coast of Chile". Copeia. 1993 (2): 545–549. doi:10.2307/1447159. JSTOR   1447159.
  3. Trujillo (2019). "Sharks in the forest: relationships between kelp physical-complexity attributes and egg deposition sites of the red-spotted catshark". Marine Ecology Progress Series. 610: 125–135. Bibcode:2019MEPS..610..125T. doi:10.3354/meps12818. S2CID   92832146.
  4. Fariña, Jose; Ojeda, Patricio (1993). "Abundance, activity, and trophic patterns of the redspotted catshark, Schroederichthys chilensis, on the pacific temperate coast of Chile". Copeia. 1993 (2): 545–549. doi:10.2307/1447159. JSTOR   1447159.
  5. Vásquez, Sara; Colin, Nicole; Hinojosa, Ivan; Poblete, Aldo; Górski, Konrad (2021). "The presence of kelp Lessonia trabeculata drives isotopic niche segregation of redspotted catshark Schroederichthys chilensis". Estuarine, Coastal and Shelf Science. 258: 107435. Bibcode:2021ECSS..25807435V. doi:10.1016/j.ecss.2021.107435.