Squantiniformes

## Defining Features

Commonly referred to as “angelsharks”, Squatiniformes have a dorsoventrally flattened body with eyes and spiracles on the top of the head. They have two dorsal fins present near the back of the body, as well as enlarged pectoral fins that are not attached to the head. The pelvic fins are similarly enlarged and the anal fin is absent. Some species in this order are viviparous while others are ovoviviparous. This order has five gill slits located on the underside of the body. The mouth is nearly terminal with nasal barbels. While their flattened appearance may make them resemble a ray, the tails of angelsharks are muscular and broad which is much more typical of a shark. Interestingly, the lower lobe of the caudal fin is larger than the upper lobe.

## Habitat and Range

Squatiniformes tend to inhabit temperate and tropical waters. They have been found to extend from the intertidal zone all the way down to depths of 1,400 meters deep. Species of this order are found all across the world in the western and eastern Atlantic ocean, southwestern Indian ocean, and western Pacific ocean.

## Fisheries Conservation and Concern

Since many live in coastal waters, angelsharks are sometimes caught as bycatch. Recently, a market has developed for angelsharks which has put a toll on angelshark populations. Even though regulations have been placed on angelshark fishing, many species are labelled as vulnerable or threatened and many populations continue to decline in number.

## Example Species in Squatiniformes

### Common Angelshark

#### *Squatina squatina*

Defining Features: Also called the "munk fish", this species has a flattened body and enlarged pectoral and pelvic fins similar to other angelsharks. This species is viviparous. Members of this species can grow to lengths of 183 cm. They have grayish or brownish coloration with white or dark spots dorsally.

Range & Habitat: These animals inhabit temperate coastal waters from depths of 5 - 150 m. They are benthic and spend most of their time on sandy sea bottoms. They are found in the Mediterranean and Black Sea as well as the United Kingdom, but they used to be widespread all over Europe.

IUCN Concern: These animals are listed as critically endangered by the IUCN. Fishing and habitat loss continue to affect their populations.

### Pacific Angelshark

#### *Squatina californica*

Defining Features: This shark features cone-shaped barbels near its mouth and a wide and flattened body with winglike pectoral fins. This species is ovoviviparous. This species can grow to lengths of 150 cm. Members of this species have grayish brown coloration with dark markings.

Range & Habitat: This species inhabits the western pacific coasts of North and South America. They are typically seen in depths of 3-200 m. These animals enjoy temperature waters such as shallow bays and estuaries as well as kelp forests.

IUCN Concern: This species is considered near threatened by the IUCN. Populations of this species are decreasing, with fishing being the primary cause of this.

## Example Species in the Gulf of Maine

### Atlantic Angelshark

#### *Squatina dumeril*

Defining Features: The Atlantic Angelshark also bears the flattened body and enlarged pectoral fins associated with this order. This species is viviparous. Members of this species can grow to lengths of 152 cm. This species is brown in coloration and may have dark spotting. There is a band of thorns running along this animal's back.

Range & Habitat: This animal is found off the coast of the eastern United States and in the Gulf of Mexico. It lives in shallow, temperature waters but may be seen at depths nearing 1300 m deep.

IUCN Concern: This species is considered to be least concern by the IUCN. Surprisingly, this species' population are actually increasing. However, being caught as bycatch still poses a risk to this species.

## References

Chondrichthyan Tree of Life: https://sharksrays.org/

Fish Base: https://fishbase.mnhn.fr/search.php

IUCN Redlist: https://www.iucnredlist.org/

Elasmo Research: http://www.elasmo-research.org/education/shark\_profiles/squatiniformes.htm

Oceana: https://oceana.org/