Impurest's Guide to Animals #106 - Bowmouth Guitarfish

And so we leap into February on the back of last weeks issue, the freaky Flat Huntsman Spider. This week we have an animal that looks like it has a bad mouth swimming around the blog Hope you guys enjoy.

_________________________________________________________________

Issue #106 – Bowmouth Guitarfish

Kingdom – Animalia

Phylum – Chordata

Class – Condricthyes

Order – Rajiformes

Family – Rhinidae

Genus – Rhina

Species – ancylostoma

Related Species – The Bowmouth Guitarfish is the only member of the Family Rhinidae (1)

Range – Bowmouth Guitarfish are found in the coastal waters of the Indian Ocean as well as in the Pacific coast of Indonesia, Papua New Guinea and North Australia

Skate of Play

Bowmouth Guitarfish are large batoid (rays, skates, sawfish and guitarfish) fish, which reach lengths of 2.5m and a weight of over 100kg. Unlike the majority of batoid fish, the Bowmouth Guitarfish has a very large dorsal fin, as well as a strong almost shark like tail, which is the source for the species alternate name of Shark Ray, that makes the animal look very differently to other guitarfish. The dorsal surface of the Guitarfish is covered in white spots which stand out against the species brown colouration and contrasts with the row of thorns running along across the head and back of the animal.

The Bowmouth Guitarfish is a nocturnal predator, feeding on fish, crustaceans and molluscs that comes across its path while hunting. Like many other batoid fish the mouth is on the underside of the animal, and prey is crushed by multiple wide bands of flat teeth, perfect for smashing open hard shelled prey. Due to its size, and the defensive rows of thorns on its back, the Bowmouth Guitarfish has very few natural predators, although the remains of adult Guitarfish have been found in the stomachs of Tiger Sharks (Galeocerdo cuvier) where their ranges overlap (2).

Bowmouth Guitarfish are viviparous, and give birth to litters of up to eleven large pups. Newly born animals are already half a meter long, but grow slowly reaching sexual maturity when they reach a length of 1.5m. Due to their slow growth, desirability for shark-fin soup, and habit of raiding fishing nets, the Bowmouth Guitarfish is persecuted across most of its range, earning the species the unfortunate nickname ‘the Panda of the Sea’ as well as status as an endangered species.

Five Brilliant Batoid Fish

It would not surprise most people to know that sharks and rays are among the most intelligent of the marine fish. What is amazing is that the filter feeding Manta Rays (Genus: Manta) have the largest brain to body mass ratio of all marine fish. In addition to large brains, Manta Rays have an organ called the retia mirabilla that keeps the brain warm and functioning when swimming in cold water (3).

Of all the rays, the stingrays have the worst reputation due to a number of recent accidents. It should be noted that the ‘sting’ of a stingray is a defensive weapon, and such incidents are not aggressive attacks, despite the claims of those who persecute them. Many stingray species, such as the Giant Freshwater Stingray (Himanturapolylepis), are endangered species and are in danger of extinction due to this aggressive bias.

When it comes to ‘a sting in the tail’ the Common Torpedo Rays (Torpedo torpedo) packs a fair punch, being able to produce electrical discharges up to 200 volts to stun its prey and defend itself.

Of all the batoid fish however, it is the Sawfish that have the most defensive weapons. That said the saw of a sawfish, such as the Smalltooth Sawfish (Pristis pectiana), serves multiple functions serving as a defensive tool, an offensive weapon, an electro-sensory organ, a shovel for uncovering buried prey and to pin food to the seabed in order to guide it to the mouth on the underside of the fish.

Whilst not being a batoid fish, the Tasselled Wobbegong (Eucrossorhinus dasypogon) shares many traits with its skate and ray relatives. The species is unique in being the only shark to use caudal luring to attract prey (4). Resting on the seabed, the shark twitches its tail (which is complete with a black eye spot) in the same way a small fish moves. When a potential predator of this ‘bait fish’ arrives, the shark quickly strikes with its large mouth and swallows the prey whole.

Bibliography

1 -www.arkive.org

2 -Simpfendorfer, C.A.; Goodreid, A.B.; McAuley, R.B. (2001). "Size, sex and geographic variation in the diet of the tiger shark,Galeocerdo cuvier, from Western Australian waters".Environmental Biology of Fishes61: 37–46.

3 - Ari, C. (2011). "Encephalization and brain organization of mobulid rays (Myliobatiformes, Elasmobranchii) with ecological perspectives" (PDF). Open Anatomy Journal3: 1–13

4 – Ceccarelli, D.M.; Williamson, D.H. (2012). "Sharks that eat sharks: opportunistic predation by wobbegongs". Coral Reefs31 (2): 471

Picture References

1 - http://cdn2.arkive.org/media/D3/D3F2B2E8-39F7-4B59-8943-8ECB980A5678/Presentation.Large/Bowmouth-guitarfish.jpg

2 - http://www.fishesofaustralia.net.au/Images/Image/RhinaAncylostomaMarjAwai.jpg

3 - http://static.ddmcdn.com/gif/blogs/6a00d8341bf67c53ef017d3ce6bb5a970c-800wi.jpg

4 - http://images.universityherald.com/data/images/full/10048/sawfish.jpg?w=600

Talk about some stunning sea-creatures (literally in the case of the Torepdo Ray) and their amazing abilities. Next week we celebrate Chinese New Year and see in the Year of the Monkey. But until then critic, comment and suggest future issues as well as making sure you check past issues in Impurest’s Bestiary.

Many Thanks

Impurest Cheese

@cbishop, @laflux, @ostyo, @wildvine, @luna_joestar, @xwraith, @cgoodness, @ms-lola,@dboyrules2011,@quinnofthestoneage,@scavengerfist,@MadeinBangladesh,@rocketraccoonthingy,@black_wreath,@captainmarvel4ever,@spareheadone,@cpt_nice,@risingbean,@pipxeroth and @theik2

What a poor skate of affairs this week's issue is in...

Should be the Plectrummouth Guitarfish

Who travel in bands

Is it an acoustic guitar fish?

@theik2: Nah it's an electric guitarfish

@quinnofthestoneage:LOL, yes it should be, but it was found before the plectrom was a thing

That's not you spell electric eel. : P

@wildvine: Electric Eel isn't even an eel BTW

@impurestcheese: Given how much they appear in cartoons, I assumed they weren't even a real thing

That's shocking!

@wildvine: Nope it's a real animal from South America. It's not an eel but actually a species of knife-fish

@theik2: Oh how much I want to resist all these electricity puns

Tiger Sharks are the ones that eat everything right?

@impurestcheese: Anything to please you. The knifefish looks kinda eel like.

Love the ridges on the guitar fish. Very striking.

@cgoodness: Aye, the Tigershark is the dustbin of the sea

@theik2: Yeah it is a case of Convergent Evolution with real eels

@spareheadone: That's where the thorns for cutting open nets are

(also where you attach the strings)

woah it doesn't even look real. Looks like from an animated film.

~MiB

@MadeinBangladesh: It does have that interesting look

Manta Ray is the Einstein fish.

@ostyo: It would seem so at the moment...further testing is required to determine actual intelligence

@impurestcheese: Awesome.

@impurestcheese: Do not question the Manta!

@laflux: Cool thanks

@ostyo: Pft yeah right

Finally, something that doesn't creep me out.

I still won't be at the beach party on Saturday, though.

I love his little face.

This fish looks so bored. I like it!

I guess it's a good a time as any to bring up the female shark who ate a male one because he bumped into her. Something like that. Automatically thought of you.

Guitarfish? Silly name, lolz.

@risingbean: Good to know (It's a primate next week so you should be safe)

@bumpyboo: Heh his face is kind of cute

@ms-lola: It looks bored? As for the shark on shark incident, well that's not suprising, Sand Tiger Sharks are cannibals before being born, the pups liturally eat each other inside the mother's womb

@dboyrules2011: It is a bit hence the alternate name 'wedgefish' is being suggested, although that's almost as silly

@impurestcheese: I didn't know that. Sharks are fierce.

@ms-lola: Yeah that we did know, at least the Bowmouth Guitarfish babies get a tasty placenta to keep them going, but for most sharks it's eat or be eaten from Day 0

@impurestcheese: I've never understood why an animal can get classified in its own family. Is it the tail for this one?

@ficopedia: It's genetically distinct from the other guitarfish, and has ancestral features (such as the high dorsal fin, rows of thorns and well developed tail fin) which make it a basal species to all the other rays, skates and guitarfish

Cool, so these guys (saw fish, rays, etc) are related huh. Poor rays, people here believe that their tails can ward off aswangs (supernatural beings who eat organs); I know cause we have one at home.

@scavengerfist: They are indeed. You have a stingray tail whip that's kind of cool if a more than a little saddening.

@impurestcheese: I've actually seen a live ray once in a fish market in our city, I don't know what happened to it after. The things we do to live...

@scavengerfist: Yep I saw that in Indonesia as well, albeit it was on its way to a marine institute for study

@impurestcheese: Cool, thanks.

@ficopedia: No problem

@impurestcheese: Nah, wedgefish sounds far cooler, yo.

I sometimes cannot tell if you're being serious or not. Did you really not know that electric eels are real?

@cbishop: Sometimes I don't know

@wildvine: lol Imp' got me with Spanish Fly (#177). I thought that was just a song. I had no idea that it was an actual insect. :)