Animal Species:Warty Prowfish, Aetapcus maculatus (Günther, 1861)

The Warty Prowfish with its distinctive warty skin that can be shed like a snake skin is only found in Australia.

Standard Common Name

Warty Prowfish

Alternative Name/s

Smooth Prowfish, Tasmanian Prowfish.

Identification

The Warty Prowfish can be recognised by its warty skin that is regularly shed like a snake skin. Its base colour can be brown, pink, orange, yellow or pale whitish. It often has dark blotches.

This species has a steeply sloping snout and a very long-based dorsal fin. It has large pectoral fins but lacks pelvic fins.

Size range

The species grows to 22 cm in length.

Distribution

The Warty Prowfish is endemic to Australia.  It occurs from northern Tasmania to central Western Australia.

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums.  Source: Atlas of Living Australia.

Aetapcus maculatus

Distribution by collection data

Ozcam map of Warty Prowfish specimens in the Australian Museums.

What does this mean?

Habitat

It occurs near sponges or algal areas in protected marine waters.

Other behaviours and adaptations

Skin-shedding

The skin-shedding process of the species was described by Alison Reynolds in 1979.  She described keeping two specimens in an aquarium and observing the skin being shed by the second specimen.  She stated that "Because it has not been recorded that these fish shed their skins in such a manner, Rudie wanted to photogaph the whole process.  The Prow Fish started to shed its skin quite regularly, once every 22 or 24 days, and typically the days it was due to shed its skin was on a long weekend and Rudie would come home to find a brilliant new skinned Prowie.  The 23rd day came around again and the Prowie's skin began to look transparent and fill up with water like a blister - during the night it filled out further and the next morning it looked like a balloon.  Eventually the skin split just behind the gills, this enabled the Prowie to fan water out of his gills and push the skin back from his head.  Another split along the underside of the jaw and with one big wriggle and a jet of water from his gills, the skin was cast off.  I have only heard of two other cases of fish shedding their skins (in the same manner a reptile would), one was a small Pegasus Fish in Guam and the second was a Velvet Fish Rudie found under Portsea Pier.  He picked the fish up to relocate it for a photograph and it swam out of his hand leaving behind a complete skin.  As this is only a newly observed phenomenon there are no really scientific theories as to why the fish shed their skins in this manner.  We believe that because these fish live a rather quiet life spending most of their time either buried in the sand or under or against rocks that a film of bacteria and algae builds up on the skin and consequently the only way to rid themselves of such growths is to shed the whole skin regularly."

Classification

Species:
maculatus
Genus:
Aetapcus
Family:
Pataecidae
Order:
Scorpaeniformes
Class:
Actinopterygii
Subphylum:
Vertebrata
Phylum:
Chordata
Kingdom:
Animalia

What does this mean?

References

  1. Gomon, M.F. in Gomon, M.F., Glover, C.J.M. & R.H. Kuiter (Eds). 1994. The Fishes of Australia's South Coast. State Print, Adelaide. Pp. 992.
  2. Hutchins, B. & R. Swainston. 1986. Sea Fishes of Southern Australia. Complete Field Guide for Anglers and Divers. Swainston Publishing. Pp. 180.
  3. Kuiter, R.H. 1996. Guide to Sea Fishes of Australia. New Holland. Pp. 433.
  4. Kuiter, R.H. 2000. Coastal Fishes of South-eastern Australia. Gary Allen. Pp. 437.
  5. Reynolds, A. 1979. The Warty Prow Fish.  Skindiving in Australia. February: 24, 26. (photos by Rudie Kuiter)


Mark McGrouther , Collection Manager, Ichthyology
Last Updated:

Tags fishes, ichthyology, Warty Prowfish, Aetapcus maculatus, Pataecidae, warty skin, skin sheds, Smooth Prowfish, Tasmanian Prowfish, brown, pink, orange, yellow, pale white, blotches/mottled, sloping snout, large pectoral fins, lacks pelvic fins, 10 cm - 30 cm, endemic to Australia, marine,

11 comments

kokosnood - 2.10 PM, 01 October 2010
What an amazing fish! Thanks for the update!
Mark McGrouther - 10.09 AM, 28 September 2010

Hi kokosnood,  Bill Boyle's wonderful images of the Warty Prowfish ejecting a cloudy fluid are now on the page above.  Thanks for your interest.  The page is now much improved.

Mark McGrouther - 5.09 PM, 20 September 2010

Hi kokosnood.  You can find information for the Snubnose Eel on the Australian Museum site now.

Mark McGrouther - 9.09 AM, 19 September 2010

Hi kokosnood,  I will hold good on my promise to add a factsheet for the Snubnose Eel, but in the meantime, I thought you might like to see part of the webpage that was on the old Australian Museum site (see comment attachment).  This page still has to be migrated to the new site.  Your enquiry has bumped it to the top of the list.  More soon.

Comment Attachment

Mark McGrouther - 4.09 PM, 18 September 2010

Hi John, Thanks for your comment. I have not visited the California Academy of Sciences - It's on my list.  Simenchelyes parasitica, the Snubnose Eel, certainly does exist.  Unfortunately I don't have a fact sheet on the site for the species.  I will do one next week and email you when it is online.  In the meantime you can learn a little about the species at the Australian Faunal Directory.

kokosnood - 3.09 AM, 18 September 2010
Mark, I live in California and have visited the Academy of Sciences many times. As an adolescent it had a profound influence on me. I consider it my favorite public aquarium. The rebuilt Academy of Sciences is amazing! I have a question about another species: In the introduction to the "Encyclopaedia of Fishes" the authors mention a parasitic eel which lives inside the heart of large sharks--Simenchelyes parasitica. I can't find any information about this fish anywhere on the internet. Perhaps the name has been changed, or there is very little information available. Can you provide some insight into this fish? Thanks!
Mark McGrouther - 9.09 AM, 16 September 2010

Hi kokosnood,  I'm very pleased to hear that your interest arose from the book.  Yes, it is a excellent publication.  The senior author, Dr John Paxton worked here at the Australian Museum for many years and is now a Senior Research Fellow.  The junior author Dr Bill Eschmeyer has also had an illustrious ichthyological career, in his case with the California Academy of Sciences.  Bill has spent many years working on the Catalog of Fishes.

kokosnood - 2.09 PM, 15 September 2010
I have that book! That is what prompted my question :) What a great book. I've had it on my shelf for years, and recently decided to read it cover to cover--in the past I've always just used it as a reference. Thanks for getting back to me!
Mark McGrouther - 11.09 AM, 15 September 2010

kokosnood, I have made some progress on the cloudy fluid front.  From what I understand, little is known of the composition of the fluid.  It is presumably toxic and is used as a response to threats from predators.  There is a fantastic image of a Warty Prowfish expelling a 'cloud' of fluid in 'Encyclopedia of Fishes'.  I have the 1994 edition edited by Dr John R. Paxton and Dr William N. Eschmeyer.  You can see the same image online at the Auscape International photo site. In the meantime, I will try to obtain an image to add to the fact sheet but this may be a tall order!

Mark McGrouther - 3.09 PM, 10 September 2010

Hi kokosnood,  That is a great question - thank you.  I have heard about the species releasing a cloudy fluid but cannot quickly track down any solid information about it.  I will do so, and post a comment soon.  In the meantime, I have updated the page with quite a long chunk of text from an old article in S.I.A about the skin-shedding behaviour of the species.  I hope you find it interesting.  More soon.

kokosnood - 1.09 PM, 10 September 2010
I am curious about the cloudy fluid released by these fish when threatened. Does anyone have any information about this?

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