Diversity and conservation of Algerian amphibian assemblages

Abstract

Fourteen amphibian species representing six families inhabit Algeria: Salamandridae (Pleurodeles nebulosus, Pleurodeles poireti, and Salamandra algira), Alytidae (Alytes maurus, Discoglossus pictus, and Discoglossus scovazzi), Bufonidae (Amietophrynus mauritanicus, Amietophrynus xeros, Barbarophryne brongersmai, Bufo spinosus, and Bufotes boulengeri), Hylidae (Hyla meridionalis), Ranidae (Pelophylax saharicus), and Dicroglossidae (Hoplobatrachus occipitalis). The presence of some of them, like A. maurus, D. scovazzi, and H. occipitalis, is punctual. Areas of distribution conform to predictable patterns of biogeography; almost all species are present only in the Mediterranean region, while the Sahara Desert relegates a few frog species to isolation in mountain areas and oases with sufficient water. Amphibian community origins are directly related to climatic changes in North Africa throughout the Holocene. Many relict populations can be explained by comparison of the former layout and structure of hydrographic networks with those currently reduced to dry beds and, on occasion, suffering hyper-saline conditions. Relatively close phylogenetic relationships between species in the north of Algeria, portions of the Iberian Peninsula, Moroccan Atlas Mountains, Mediterranean islands and the Italian Peninsula, demonstrate that Algerian amphibian communities have as their origins the same Tertiary geological events that gave rise to today’s Mediterranean Sea. In the northern Mediterranean region, human overpopulation of coastal areas is affecting water quality and amphibian species diversity. The relict character of many amphibian populations in the desert regions, along with the rarity of stable water due to a combination of natural climatic changes, over-exploitation of aquifers, and eutrophication or pollution, justifies considering all species to be in danger to one extent or another. Using IUCN-proposed criteria as a guide, we herein suggest a catalogue of threatened amphibian species, provide a preliminary list of areas of interest, and suggest appropriate action necessary for amphibian conservation in Algeria. Of the 14 amphibian species known from Algeria P. poireti, a newt found only in the Edough mountains, the Guerbes-Sendhadja wetlands, and the Mekhada marshes, and A. maurus, a toad whose only known population in Algeria is in the Tlemcen mountains, must be considered Critically Endangered according to our suggested catalogue. We also consider P. nebulosus to be Threatened and S. algira to be Vulnerable, each due to continued loss of habitat, rarity, and population fragmentation. Finally, all amphibian populations south of 32°N latitude should be considered Near Threatened.