took it to Colchester's Natural History Museum where it was identified as a neotenous
smooth newt.
The newt, which was given the name Neo, was featured on Anglia News and in the
local press. The newt measures about 7cm in length (snout to tip of tail) and is a light
yellow/brown on the back (see plate 2 inset), more pinkish on the belly. The throat is
whitish and the eyes, pigmented. The overall impression is of a much paler animal than,
for example, atypical female smooth newt. . On either side of the back of the head are
plumose red-pink gills. A membraneous fin runs from the back, just behind the forelegs,
around the tail to the vent.
The newt is sluggish, spending most of its time motionless on the bottom or walking
slowly along, although it can move rapidly when necessary to take bloodworms
(Chironomus sp.) and other small prey. It has never been observed to take air at the
surface of the water.
The older literature terms this condition neoteny although it is perhaps more accurately
referred to as paedomorphosis, i.e. the retention of juvenile features in the adult. Animals
showing total neoteny are able to go on to breed successfully whereas those that exhibit
partial neoteny continue to grow without metamorphosis occurring, but are unable to
breed. (Griffiths 1995).
The causes of paedomorphosis are not fully understood, older works such as Smith
(1969) cite large amounts of organic matter in the water and/or steep sides to the pond
as favouring the condition but more recent works suggest that an abnormal pituitary
gland is the cause (Griffiths loc.cit.) The pituitary also regulates pigmentation that is
lacking in man)' paedomorphic newts.
The condition appears to be quite rare, in a population of 1500 newts studied in York
only one individual exhibited neoteny (Griffiths loc.cit.). It is certainly the first example
seen by the author in over 40 years of pond dipping!
Neo is now installed in its own aquarium in the Museum and has proved a popular
attraction with visitors.
Acknowledgement
I would like to thank Mr and Mrs Clarke for drawing the newt to my attention and
subsequently donating it to Colchester Museums.
References
Griffiths, RA. (1995) Newts and Salamanders of Europe. London, Poyser
Smith, M. (1969) The British Amphibians and Reptiles. 4"' ed. London, Collins
16
Essex Field Club Newsletter No. 43, January 2004