All about Dogfish!!!!

[DarkSkies]

I know people are just gonna love this thread!! Our favorite bottom dweller!!! :


Post up anything you want to about dogfish, facts, figures, pics, anything at all you feel like throwing up here.

If whatever you quoted comes from a published or copyrighted source, please add the link. Thanks.

[crosseyedbass]

OK I hate dogfish, so I might be accused of having a bias. Every time I do I search on them I hate them more. They are like the cockroaches of the sea, it seems there is no getting rid of them. But I did find some basic info. I still hate them with a passion, and could care less if they became extinct, though that will never happen.

Smooth dogfish



Mustelus canis
Smooth Dogfish [+]

Kingdom: Animalia
Phylum: Chordata
Class: Elasmobranchii
Order: Carcharhiniformes
Family: Triakidae
Genus: Mustelus
species: Mustelus canis
+ITIS +WoRMS +Conservation Status

Smooth Dogfish Photo Gallery
Description & Behavior

The smooth dogfish, Mustelus canis (Mitchill, 1815), aka dusky smooth-hound, Atlantic smooth dogfish, dogfish, dusky smooth hound, dusky smoothhound, grayfish, nurse shark, smooth dog, smooth hound, and smoothhound, measures about 150 cm in total length and weighs a maximum of 12.2 kg. This is a small shark species with two well-serrated dorsal fins almost equal in size. The first dorsal fin is slightly larger. The second dorsal fin is found slightly in front of the anal fin, which is about half the size of the second dorsal fin. There are two tail lobes; the lower lobe is rounder and shorter than the upper lobe and the rear lobe has a deep notch near the tip. This species has a tapering, blunt snout and a spiracle behind each narrow eye.













ShareCreateApture™
by Fred


Species within the genus Mustelus are characterized by their flat, blunt dentition, which is much different than other shark species that have sharp, blade-like teeth. The small teeth of the smooth dogfish are of similar size in the upper and lower jaw and are asymmetrical in shape with a rounded apex. They have between 8-10 rows of teeth used to crush and grind their food rather teeth used to bite and tear as in other shark species.
Although the geographic range of the smooth dogfish overlaps that of the spiny dogfish Squalus acanthias, the two are easily distinguished by the presence of a single spine in front of each of the two dorsal fins of the spiny dogfish.
M. canis has a subspecies, M. canis insularis, which is identical to M. canis with the exception of a slightly higher dorsal fin and a longer caudal fin tip in M. canis insularis. In addition, M. canis insularis also has more vertebrae than M. canis. M. canis is also confused with M. norrisi, the Florida smoothhound, which has a lower caudal lobe with a sharp point at the tip.
The smooth dogfish varies in color from gray to brown with a yellow-gray to white ventral side. This species can change its color by contracting its melanophores to blend into its surroundings.
Smooth dogfish are born with a first dorsal fin that is dusky gray in color at the edges. The apex of the second dorsal fin is also dusky gray and has a white rear edge with a white-edged tail fin. These markings fade by the time the shark is about two feet in length.
World Range & Habitat

The smooth dogfish, Mustelus canis, is found in subtropical waters between 42°N-44°S and 100°W-46°W up to a max depth of 579 m deep. They are a migratory species found in abundance off the coasts of the US. Their range includes the western Atlantic from Massachusetts to Florida, the northern and western Gulf of Mexico, the coasts of Venezuela, Cuba, Jamaica, Barbados, Bermuda, Bahamas, and southern Brazil to northern Argentina, and the Antilles. The smooth dogfish tends to inhabit continental and insular shelves and upper slopes in depths that range from shallow inshore waters and the intertidal zone around 18 m up to the max depth of 579 m. Although this species has been seen in freshwater, it is unlikely that the smooth dogfish can survive in fresh water for extended periods.
» GBIF occurrence data in Google Earth [Requirements | Tips] | Ocean Biogeographic Information System (OBIS) [World Map] | [about]
Feeding Behavior (Ecology)

The smooth dogfish, Mustelus canis, feeds nocturnally on large crustaceans, including crabs and lobsters, and on shrimp, small fish, and mollusks. They are preyed on by other shark species including: Carcharhinus plumbeus, C. carcharias, C. obscurus, C. limbatus, and Sphyrna mokarran.
Life History

The smooth dogfish, Mustelus canis, has a low, minimum population doubling time of 4.5-14 years. This species is viviparous and gives birth to 4-20 pups per litter after a gestation of 10-11 months. Mating occurs between May and July. Females are able to store live sperm, although it is unknown whether stored sperm can be used to actually fertilize their eggs. Pups are born measuring 34-39 cm in length and grow quickly. Males reach sexual maturity between 2-3 years of age or 68-93 cm, females between 4-5 years and 70-130 cm. Female smooth dogfish are thought to live about 16 years, males 10.
Viviparous: the embryo develops inside the body of the female from which it gains nourishment from a yolk-sac placenta.
Population doubling time: a measure of a species' resilience, or its capacity to tolerate exploitation.
Comments

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The smooth dogfish, Mustelus canis, is caught commercially and as a gamefish. It is probably considered bycatch in most fisheries.
The smooth dogfish is listed as Lower Risk/near threatened (LR/nt) by the IUCN Red List of Threatened Species:
LOWER RISK (LR) - A taxon is Lower Risk when it has been evaluated, does not satisfy the criteria for any of the categories Critically Endangered, Endangered or Vulnerable. Taxa included in the Lower Risk category can be separated into three subcategories:
1. Conservation Dependent (cd). Taxa which are the focus of a continuing taxon-specific or habitat-specific conservation programme targeted towards the taxon in question, the cessation of which would result in the taxon qualifying for one of the threatened categories above within a period of five years.
2. Near Threatened (nt). Taxa which do not qualify for Conservation Dependent, but which are close to qualifying for Vulnerable.
3. Least Concern (lc). Taxa which do not qualify for Conservation Dependent or Near Threatened.


http://marinebio.org/species.asp?id=1157

[crosseyedbass]

View all available Spiny Dogfish Pictures

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Common Names: </B>Spiny dogfish, Common spiny dogfish, Piked dogfish, Mud shark.
Latin Name: Squalus acanthias
Family: Squalidae
Identification: Long, flattened, pointed snout. Grey to brown above usually with small white spots. White spots may follow lateral line. Eyes large. Mildly venomous spines on first and second dorsal fins. Anal fin absent. Belly white.
Size: Maximum length 1.6 meters. size at birth 22-33 cm. Maximum recorded age 66 years.
Habitat: Often cruise over sand and mud bottoms. Also frequently encountered over rocky reefs. From 0 to 900 meters. Inhabits estuarine, coastal and offshore waters sometimes migrating over great distances - 30 tagged individuals traveled from British Columbia to Japan, 7000km! Newfoundland tagged individuals have been captured years later in Iceland. Normal migration patterns are usually more localized; both Atlantic and Pacific groups migrate between Canada and the US in order to stay within a seasonal temperate range.
Abundance and distribution: Worldwide in temperate seas. Known on the Atlantic coast from Labrador to the Gulf of Mexico and on the Pacific Coast from the Aleutians to Central Baja. Once thought to be the most abundant shark in the world the Spiny dogfish is now facing commercial extinction and a grass roots movement around the world is attempting to lobby for a reduction in quotas. In the UK and Europe Spiny dogfish are the principal fish utilized in "fish and chips". It is also ground up to be used in fertilizers.
Behavior: Cruises over soft bottoms either alone or in small groups. Occasionally schools (often segregated by sex) in response to food supply such as squid or salmon runs. May also form schools with other species such as leopard sharks and smoothhounds. Diet consists mainly of bony fishes. Other foods include octopus, squid and crustaceans.
Reproduction: Ovoviviparous. Litter size from 1- 20. Spiny dogfish have a slow maturity rate (around 12 years) which makes them very vulnerable to over fishing. They also have the longest gestation period of any known vertibrate 18-24 months.
Observations:
Photographs: Saanich inlet, Vancouver Island.
Similar species: Smooth Dogfish mustelus canis which has a sympatric range from the Bay of Fundy to the Gulf of Florida and from Southern Brazil to Argentina.


http://www.elasmodiver.com/spiny_dogfish.htm