skate/ thornie

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paulocallaghan · #1 Post by **paulocallaghan** » Mon May 21, 2007 12:00 pm

pls correct me if im wrong but skate and thornback ray are 2 different species, so why do some people use the terms as if they are interchangable.

#2 Post by **pete** » Mon May 21, 2007 12:04 pm

Its more a commercial thing, or rather used to be. All ray species traditionally were given the generic title of skate. Same kind of story with monk/anglerfish

#3 Post by **coaster** » Mon May 21, 2007 3:40 pm

The common name for them is thornback skate. As far as I can tell they are only known as thornback ray in the UK.
They have a vast range and are thornback skate everywhere else.

#4 Post by **coaster** » Mon May 21, 2007 3:46 pm

Common Names: Thornback skate, Thornback ray (UK).

Latin Name: Raja clavata

Family: Rajidae

Identification: Rounded snout gives way to mildly concave anterior margins of pectoral fins. Distinct nub at tip of snout. Posterior margins of pectoral fins slightly convex. Small and large thorns extend down back and tail. Pattern of irregular sized pale spots and light and dark patches cover dorsum. Overal colouration may be grey or brown.

Size: Maximum length 90cm

Habitat: Found on sand and mud bottoms occasionally adjacent to rocky reefs. Intertidal to 300m.

Abundance and distribution: Common in eastern Atlantic from Norway south throughout the Mediterranean, the western Baltic, and the western Black Sea.

Behavior: Usually seen lying motionless on sand. Forages for a variety of benthic animals such as crustaceans.

Reproduction: Oviparous. Large females may lay upto 150 egg capsules during one season.

http://www.elasmodiver.com/Thornback%20skate.htm

#5 Post by **pete** » Mon May 21, 2007 4:01 pm

Thats interesting Coaster, I've never heard of them being refered to as thornback skate.

#6 Post by MC » Mon May 21, 2007 4:29 pm

same here i have always know them as ray and it was just the large ray where know as skate

paulocallaghan · #7 Post by **paulocallaghan** » Mon May 21, 2007 4:57 pm

so are our 5lb thornback ray and 200lb skate the same fish just one is a bit older than the other

#8 Post by **Tanglerat** » Mon May 21, 2007 5:08 pm

Entirely different fish.

#9 Post by **EoinMag** » Mon May 21, 2007 6:16 pm

I just had a look in the fishbook from the CFB.
There are three skate species and about 15-20 rays listed, they say this to them.
"The larger species are commonly referred to as 'skates' while the smaller species are called 'rays'."

jw · #10 Post by jw » Mon May 21, 2007 8:42 pm

the book is wrong on this point...... consider the manta ray

teacher · #11 Post by **teacher** » Mon May 21, 2007 11:56 pm

I better begin by saying that I know almost *nothing* about skates or ray, but the internet can make anyone an authority on anything. :lol:

A small bit of digging suggests that the name Skate refers to the family Rajidae (Skates). In common Engling usage (OED), however, it seems to refer particularly to the genus Raja and particularly to the Raja batis ("Common Skate" or "Blue Skate"). Raja clavata is the Thornback ray.

Edit: looking at the CFB "Fish Book", I would say that any "Ray" there, with the exception of Electric, Howned, Eagle and Sting Rays, could be refered to as a Skate.

#12 Post by **stevecrow74** » Tue May 22, 2007 1:32 am

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes (cartilliganeous fish)
Subclass: Elasmobranchii (sharks and rays)
Order: Rajiformes (rays, sawfishes, and skates)
Family: Rajidae (skates and rays)
Species:
* Common Skate, Raja batis
* Thornback ray, Raja clavata

now also, the reference for common skate was made back in 1810
and the reference for thornback ray dates back to 1758

if you do the same for humans you'll find that in the sub species (i.e. the difference between ray and skate) that chimpanzee'z and humans there is no major classification.. see below

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Haplorrhini
Infraorder: Simiiformes
Parvorder: Catarrhini
Superfamily: Hominoidea
Family: Hominidae
Species:
* Subfamily Homininae
* Gorilla - gorillas
* Pan - chimpanzees
* Homo - Humans
and that reference was classed back in 1825..

#13 Post by **coaster** » Tue May 22, 2007 9:37 am

For those of us that don't speak Latin. :lol:
What are you saying.
Ray or skate. :?:

teacher · #14 Post by **teacher** » Tue May 22, 2007 9:42 am

coaster wrote:Ray or skate. :?:

Yes

#15 Post by **coaster** » Tue May 22, 2007 9:43 am

:lol:

#16 Post by **stevecrow74** » Tue May 22, 2007 9:52 am

coaster wrote:For those of us that don't speak Latin. :lol:
What are you saying.
Ray or skate. :?:

what i'm saying is monkey or human... that is the difference...

#17 Post by **coaster** » Tue May 22, 2007 9:55 am

stevecrow74 wrote:
coaster wrote:For those of us that don't speak Latin. :lol:
What are you saying.
Ray or skate. :?:

what i'm saying is monkey or human... that is the difference...

But the question was about fish, not you. :P

teacher · #18 Post by **teacher** » Tue May 22, 2007 10:06 am

It appears to me (as I said) that the name Skate could apply to three things, each one a subset of the other:

The family Rajadae seems to be referred to by the English name Skate (but it's not clear whether Skate is some or all of the fish in this family)

The OED tells us that the name Skate is a fish of the genus Raja (which is in the family Rajidae)

The OED also tells us that the name Skate especially refers to the Raja batis or Common Skate.

Going back to the original question, what I would refer to as a thornback ray could also be referred to as a skate.

I guess the answer is that if you want to be precise (or pedantic like Crow :P) use the scientific classification .

#19 Post by **stevecrow74** » Tue May 22, 2007 10:07 am

the difference between a skate and a ray is like comparing the difference between a chimp and yourself, a domestic cat and a lion... they are of the same family order but differ in gene's (and no i'm not talking about denim and levi's) :? which make them different...

its only those that dont know the difference(non-fisher folk) that dont/cant differentiate between the species.. they just see big flat ugly things that all look the same no matter what size they are..

#20 Post by **stevecrow74** » Tue May 22, 2007 10:08 am

teacher wrote:(or pedantic like Crow :P)

just being specific..