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ON MELANISTIC TENDENCIES IN DEATH ADDERS, ACANTHOPHIS ANTARCTICUS (SHAW).

By:Raymond T. Hoser, Then of: 170 Lawson Street, Redfern N.S.W. 2016, Australia.
1996 address: 41 Village Avenue, Doncaster, Victoria, 3108, Australia. Fax: +61 3 9857-4664.

This article was originally published in August 1985 in Litteratura Serpentium 4 (5), pp. 157-159. It had been written some years earlier. What follows is a text only (no italics) version.

Female Death Adder - Acanthophis antarcticus - From West Head, New South Wales, Australia.  This is the snake that was the subject of this paper.  She was stolen from this author on 10th July 1984 by Corrupt Officials with the New South Wales National Parks and Wildlife Service.Introduction.

The author has held a number of death adders since late 1978. All 12 death adders involved in my Acanthophis antarcticus studies, are from the Sydney district and consist of 7 red phase and 5 grey phase snakes. Three of these snakes of the grey phase have had their colours become considerably darker, approaching a dark grey black in colour. It is interesting to note that no red phase death adders showed any melanistic tendencies. It is also interesting to note that not all grey death adders held by myself have melanistic tendencies. It should be noted that the three grey death adders with melanistic tendencies are the largest and most heavily built three, though definitely not the oldest three grey death adders held by myself. Various reasons have been postulated for the melanistic tendencies in the three death adders concerned. I have reservations about all reasons except for the fact that some feature of captivity does induce it.

1. Heating of snakes. Many death adders held by myself are heated and hence the correlation between heating and colour darkening appears obvious, however, one death adder (AAA-2) experienced maximum darkening whilst unheated for over 12 months. Thus this conclusion appears doubtful.

2. Natural ageing processes. Among the specimens concerned, as they have aged they have tended towards melanacy. This melanistic tendency also has a correlation to the period of time in captivity. One death adder (AAA-11) showed marked melanistic tendencies whilst in the late juvenile stages and is now highly melanistic although only a young adult. No wild death adders from the Sydney district including large old adults observed by myself have shown nearly as strong a tendency for melanism as the three captive specimens mentioned. Dulling of colouration is definitely a feature of ageing in death adders, but tendencies towards melanism is not a feature of wild death adders.

3. Captivity stress. There is no evidence that death adders held by myself are under any form of stress. None have ever died in my possession and they thrive and breed. It has never been shown previously that a stressed snake will over an extended period of time grow darker in colour.

Table 1. Detailsof the three melanistic Death Adders.

      Catalogue Nr. AAA-2 AAA-3 AAA-11

      Point of origin Glenbrook Terry Hills Glenbrook
      N.S.W. N.S.W. N.S.W.
      Sex F F M

      Date caught 14.12.1978 24.12.1978 19.2.1980
      (Day/month/year)
      Length when
      caught 46.5 cm 43.5 cm 45 cm

      Length on
      1.6.1981 64 cm 65.7 cm 73 cm

      Date of first
      melanistic
      tendencies Jan. 1980 Jan 1980 May 1980

The melanism in Acanthophis antarcticus observed is obviously only dorso-lateral in extent. This colour change in Acanthophis antarcticus is significant as elapids are a group of snakes generally recognised as being unable to change their colour under "normal" circumstances.

REFERENCE:

Prust, E., 1984. Albinism in snakes. Litteratura Serpentium, Vol. 4 (l): 6-15 / Dutch ed.: 7-16.

Editorial note: In Litteratura Serpentium, Vol. 5, No. 6, a colour picture of a "melanistic" Acanthophis antarcticus (AAA-2) will be published. (The same snake AAA-2 female was depicted on the rear of the book Australian Reptiles and Frogs, by the same author).

Death Adders (Genus Acanthophis): An overview, including descriptions of FIVE new species and ONE subspecies An 11,000 word paper in Monitor - Journal of the Victorian Herpetological Society published in April 1998.

Raymond Hoser has been an active herpetologist for about 30 years and published over 120 papers in journals worldwide. He has written seven books including the definitive works "Australian Reptiles and Frogs", "Endangered Animals of Australia" and the controversial best sellers "Smuggled - The Underground Trade in Australia's Wildlife", "Smuggled-2", "Victoria Police Corruption" and "Victoria Police Corruption - 2"

  Out of control:   Crime www.policecorruption.com
....Previously covered-up info.

Papers about reptiles and frogs that can be downloaded via the internet.

Imagine a picture of a mailbox here! E-Mail inquiries to Raymond Hoser adder@lexicon.net