Skin mechanics and morphology of two species of Pachydactylus (Reptilia: Gekkonidae)

Bauer, A.M. ; Russell, A.P. ; Shadwick, R.E. (1993)

The original publication is available at http://africanzoology.journals.ac.za/pub

Journal Article

The southern African species Pachydactylus namaquensis is one of only a few mainland species of geckos that exhibits the escape strategy of regional integumentary loss. The skin morphology and mechanics of this species were compared to the same parameters in the sympatric congener P. bibronii. The tensile strength and modulus of elasticity of the skin of both species fall in the middle range of values for geckos as a whole. Skin of P. namaquensis, however, has approximately half of the tensile strength 01 that of p, bibromi. As in other skin·losing forms, the morphological basis for weakness lies in the bilayering of the dermis and the presence of zones of weakness within the upper layer of the dermis. Field experience suggests that P. namaquensis does not lose the skin as easily as most geckos exhibiting regional integumentary loss. In this species this escape strategy has probably evolved in response to the prey subjugation mode employed by rock-dwelling lizard predators.

PachydactyJus namaquensis van suidelike Afrika is een van slegs 'n paar vasteland-geitjies wat die ontsnappingstrategie van regionale velverlies vertoon. Ole moriologie en meganika van die vel van hierdie spesie is vergelyk met die van P. blbronii, 'n simpatriese lid van dieselfde genus. Die spansterkte en modulus van elastisiteit van die vel van albei spesies val in die middelgebied van waardes vir geitjies in geheeL Die vel van P. namaquensis het ongeveer die helfte van die spansterkte van die van P. bibron;;. Net soos in ander vorme wat die vel verloor, IS die morfologiese basis vir swakheid gelee in die tweelagigheid van die dermis en die aanwesigheid van sones van swakheid in die boonste laag van die dermis. Ondervinding in die veld dui daarop dat P. namaquens;s nie so maklik die vel verloor soos ander geitjies wat regionale velverlies toon nie. In hierdie spesies het hierdie ontsnappingstrategie waarskynlik ontwikkel in reaksie op prooi-onderwerpingsmetodes wat deur rotsbewonende akkedisvreters gebruik word.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/22005
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