A NEW SUBSPECIES OF Strophurus INTERMEDIUS (SQUAMATA:GEKKONIDAE) FROM SOUTH AUSTRALIA.

Raymond Hoser

488 Park Road

Park Orchards, Victoria, 3114, Australia.

E-mail: adder@smuggled.com

First published in hard copy in Boydii (Journal of the Herpetological Society of Queensland), Spring 2005.

ABSTRACT

A new subspecies of Strophurus intermedius, namely S. intermedius burrelli subsp. nov. is described from Ardrossan, South Australia Lat. 34137'S Long. 722'E. It differs from the nominate form in terms of colouration and habits. This subspecies probably accounts for all S. intermedius from the south-western part of the species range.

INTRODUCTION

Southern Spiny-tailed Geckos (Strophurus intermedius), otherwise formerly known as Diplodactylus intermedius have been familiar with herpetologists in Australia for many years. They are also commonly kept and bred by private reptile keepers.

According to Hoser (1989) they are found throughout semi-arid parts of Southern Australia, and the Macdonnell Ranges in the Northern Territory.

As adults they attain 10-12 cm in total length (on average). Most specimens are found during the day under tree bark, or in upright tree hollows. In areas without trees specimens may be caught under rocks (Hoser 1989). This nocturnal lizard is able to exude a sticky substance from the spines in its' tail when harassed. Adult females produce two eggs at a time. Breeding in the wild appears to be restricted to the warmer months, which is in contrast to at least some other species found in the same areas (see below).

As in most Australian geckos, sexing of adults is easy.

Males have large hemipenal bulges above the vent. In females the region around the vent is flat in profile.

Photos of this species appear in many books and publications, including at the top of page 69 of Hoser (1989) and a colour description is best derived from one of these photos.

Notwithstanding this, the species is generally greyish above with a pattern (usually) and is light creamish-grey below.

In two semidistinct rows, are small blunt orange-brown spines at more-or-less regular intervals, becoming more prominent towards the rear body and tail (in non-regenerated tails).

These lizards will exude or squirt an orangeish brown fluid from these spines if provoked.

To get a lizard to do this, it's easiest to rub the upper tail, being careful not to apply too much pressure or else the tail may be shed (via a process known as autotomy).

If and when the tail is shed, it invariably sheds from a single connection point near the base, which is in contrast to most small skinks (in Australia), which will shed at almost any point where pressure is applied.

However shedding of the tail is a defence of last resort for this species.

Most adults found in the wild still retain original tails.

The eye is usually orangeish brown in colour and the inside of the mouth is a deep dark blue colour.

When agitated, these lizards will open their mouth wide and charge an aggressor.

At the same time they will let out an audible barking sounS.

Strophurus INTERMEDIUS INTERMEDIUS OGILBY 1892

This is the nominate form fitting the description above.

Also refer to the papers by Kluge (1967) and Ogilby (1892).

The type locality (via lectotype) is the interior of NSW.

Strophurus INTERMEDIUS BURRELLI SUBSP. NOV.

HOLOTYPE

An adult male from Tiddy Widdy Beach, 1 km north of Ardrossan, on the Yorke Peninsula, South Australia, Lat. 34137'S Long. 722'E, lodged in August 2003 at the National Museum of Victoria. Specimen number is D71584.

PARATYPE

An adult male from Tiddy Widdy Beach, 1 km north of Ardrossan, on the Yorke Peninsula, South Australia, Lat. 34137'S Long. 722'E, lodged in August 2003 at the National Museum of Victoria. Specimen number is D71585.

DIAGNOSIS

Strophurus intermedius burrelli subsp. nov. is differentiated from S. intermedius intermedius as diagnosed in Cogger (2000), and to which it would otherwise key out as, by several traits.

Strophurus intermedius burrelli subsp. nov. is characterized by darker, more brown than orange spines on the rear body and tail than is seen in S. intermedius intermedius. The easiest way to see this difference is by comparing typical specimens of each subspecies.

The two forms can also be separated by distribution.

Strophurus intermedius burrelli subsp. nov. is currently only known from the Yorke Peninsula in South Australia, but probably accounts for all S. intermedius from the western part of the species range.

By contrast S. intermedius intermedius is probably restricted to inland NSW and immediately adjacent areas.

The status of specimens from central Australia isn't known, but may be another as yet undescribed subspecies.

Strophurus intermedius burrelli subsp. nov. is also separated from S. intermedius intermedius in terms of biology and habits.

Strophurus intermedius burrelli subsp. nov. is more inclined to open it's mouth and make a sound than is S. intermedius intermedius. It is also more likely to squirt fluids from it's tail than is seen in most S. intermedius intermedius.

While S. intermedius intermedius has a preference for resting by day under bark, in upright hollow logs or occasionally under rocks, Strophurus intermedius burrelli subsp. nov. instead prefers to hide in vegetation.

While it may appear that this shift in biology is due to different habitats inhabited, observations of Strophurus intermedius burrelli subsp. nov. in the wild indicated that this shift is also a trait of the subspecies, because where tree bark and upright hollow logs were present the subspecies Strophurus intermedius burrelli subsp. nov. still chose to reside by day in vegetation.

In terms of potential predators for either subspecies, none are known.

On 12 August 2003 an adult male Strophurus intermedius burrelli subsp. nov. was found sheltering under a small sheet of tin resting on top of an adult (65 cm) female Death Adder (Acanthophis antarcticus cliffrosswellingtoni).

While it is obvious that the distributions of both subspecies of Strophurus intermedius have become fragmented as agriculture has taken over much of southern Australia, it is uncertain as to how much gene flow occurred between the two subspecies before European settlement of Australia.

Notwithstanding this, it is evident that DNA properties between the two subspecies would differ and that specimens of both subspecies could be separated from one another by comparative DNA analysis.

In the wild state on 15 August 2003, I was fortunate enough to be able to observe 8 adults including both sexes in the wild state at Tiddy Widdy Beach.

None were noticeably gravid. This was in sharp contrast to the 20 adult Marbled Geckos (Christinus marmaratus) observed on the same day in the same locality and sharing the same microhabitat. Most, if not all adult females were noticeably gravid and by my (crude) estimate due to lay their eggs within about four weeks.

ETYMOLOGY

Named in honour of reptile keeper and breeder, Roland (Roly) Burrell, of Reynalla, South Australia, who has over many years bred and supplied to the captive trade hundreds of reptiles. He has been particularly successful with Death Adders (Acanthophis spp.), including the variant known from the type locality of this gecko subspecies.

CONSERVATION

The subspecies is common where it occurs and is probably common in other areas of suitable habitat within the Yorke Peninsula and nearby regions.

As a reptile, it's collection and keeping is regulated by the wildlife laws of South Australia and other Australian states. As there is little demand for this species in the pet trade, much of the regulation in terms of this taxa is probably not necessary.

There are no known threats to this taxa, although perhaps the greatest risk to this and other "non-threatened" Australian taxa is from exotic diseases that may be brought into Australia via the legal or illegal trade in non-native species.

REFERENCES

Cogger, H. G. 2000. Reptiles and Amphibians of Australia (Sixth edition), Reed/New Holland Publishers, Sydney, Australia:808 pp.

Hoser, R. T. 1989. Australian Reptiles and Frogs. Pierson and Co., Mosman, NSW, 2088, Australia. 238 pp.

Kluge, A. 1967. Systematics, phylogeny and zoogeography of the lizard genus Strophurus Gray (Gekkonidae). Australian Journal of Zoology 15:1007-1108.

Ogilby, J. S. 1892. Descriptions of three new Australian Lizards. Records of the Australian Museum 2:6-11.

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