Ecological distribution of snakes' fauna of Jazan region of Saudi Arabia

This study was carried out in Jazan region in the Southwestern part of Saudi Arabia, bounded in the south and east by the Republic of Yemen, Asir area in the north and the Red Sea in the west. The study area is one of the richest regions of the Kingdom of Saudi Arabia with animal biodiversity, where the region is characterized by the presence of a large group of wild animals that belong to different animal families. This work is devoted to the study of the biodiversity and geographical and ecological distribution of snakes found in the region. The results showed that there are 36 species of eight families of snakes living in Jazan region; family Typholopidae represented by two species, while families Leptotypholopidae, Boidae and Atractaspididae represented by one species only respectively; whereas family Colubridae was the most represented one having 12 species, and family Elapidae was represented by three species. Family Viperidae was represented by six species and family Hydrophiidae represented by ten species. Nevertheless, this work concentrated on terrestrial snakes. This work was suggested to throw light on the biodiversity of snakes' fauna in Jazan region as an important part of the ecosystem that has to be maintained. Since there are no enough studies on the animal species in the region. The study included also the discussion of snakes that were ecologically surveyed in the study area according to: zoogeography and temporal distribution, mode of feeding, type of food and behavior. Despite the fact that these snakes may be harmful to human life in some cases, it may also be useful to him in many aspects of life, the study showed the relationship between these snakes and human. It also threw light on the economical, medical, and scientific importance of these snakes as well as their importance for the process of environmental balance. The study presented some methods of the conservation of these species as one of the natural resources that must be maintained for not being a victim of extinction.


INTRODUCTION
Reptiles have generally a low ability to withstand changes in habitat and dispersal being particularly dependent on environmental condition for survival; they are therefore indicator species of habitat and climate.Few have actually evolved adaptation peculiarities to life in the Sahara desert (Abuzinada et al., 2004).
Snakes specially play an important role in the ecosystem.Also, they are important in the control of rodents and insects populations in the nature.Venomous snakes are economically and medically important.Venoms of some snake species

The Study Area
The present work was carried out in Jazan region.The region of Jazan is in the South-Western part of Saudi Arabia between longitudes 42 o & 43 o .80'and latitudes 16 o & 17 o , and is bounded on the South and east by the Republic of Yemen, Asir area in the North and the Red Sea in the West.Jazan region is away from the city of Riyadh with a distance of 1000 km and the holy city of Mecca with a distance of 500 km.The region is distinguished with its ideally situated on the southern Red Sea coast with a coastline of almost 300 km, and its towering green mountains in the Eastern region.The region is followed by several islands in the Red Sea, the most important and largest one is the island of Farasan.The estimated area of Jazan region is about 40000 km 2 and this means that it occupies an area of 6% of the Kingdom of Saudi Arabia.Jazan Province includes about 5,000 villages and cities.Its major city, Jazan, is home to the Port of Jazan, Saudi Arabia's third most important port on the Red Sea.Other cities include Sabya, Abu Arish, Farasan, Ad-darb, and Samtah Fig.

Climate and Topography of the Study Area
Average temperature in January is about 23°C and in August about 33°C, and the average relative humidity in January is 74%, 66% in August and 68% over the whole year.Rain fall in winter, spring and autumn, rate of fall is more than 600 mm 3 /y and more in the mountain areas.The rainfall on coasts of Jazan has a rate of more than 300 mm 3 /y.As for the mountain regions in Jazan, the temperature degree is moderate in summer and so cold in winter and cool air almost throughout the year in mountainous areas and rainfall all over the year.Topography of Jazan is varied and distinguished.We find mountais, vallies, rocky and sandy deserts, semidesert, and cultivated lands.Climate and topography of Jazan make it includes different habitats that are suitable for oproximately all species of snakes.

Surveying Snakes in the Study Area
The survey of snakes of Jazan depended on the collected material, direct observations, and other indirect evidences such as tracks or burrows, while some information were based on records available in the literature.Field trips were carried out to different locations of Jazan region of Saudi Arabia.The most favourable time for collection is between March and July, when environmental conditions are most suitable for animals to emerge.Snakes were obtained by putting a hard stick on the head and pressing with stick on the snake head in such a manner that the snake could not move its head or its jaws, then, the snake was held with the thumb and forefinger just behind the head pulling of snakes out of holes or crevices by their tails many injure them seriously.Date, locality, Co-ordinates: latitude, longitude and altitude, have been recorded by a GPS (Table 1), time of day and other ecological information were recorded.Specimens in the collection were identified by standard keys (Marx, 1968;Leviton et al., 1992;Schleich et al, 1996).The status of each species was identified according to IUCN (2005).

Species composition of Snake Fauna of Jazan
The snake fauna of Jazan consists of 36 species belonging to eight families (Typhlopidae, Leptotyphlopidae, Boidae, Colubridae, Atractaspididae, Elapidae, Viperidae, and Hydrophidae).Terrestrial species consists of 26 species belonging to seven families.Families Leptotyphlopidae, Boidae and Atractaspididae are represented by a single species of each.Family Typhlopidae is represented by two species, while family Elapidae is represented by three species in two genera Walterinnesia and Naja.Family Colubridae was found to be the most widespread and distribution that it is represented by seven genera and twelve species (Lytorhynchus, Malpolon, Platyceps, Psammophis, Spalerosophis, Dasypeltis and Telescopus).Species of the former genus Coluber were updated and the newly adopted names (Platyceps) are included.Family Viperidae includes five genera (Cerastes, Echis, Bitis and Pseudocerastes) with six species (Table 2).Hydrophiidae represents 20.8 % from total of snakes of Jazan.It includes 10 species, most of these species are poisonous snakes.Nevertheless, in this search concentrated on terrestrial snakes without concentrating on the aquatic Hydrophiidae species.(2005).
diversity of the study area.A total of 26 species of teresstrial snakes have been recorded from Jazan region belonging to 7 families.

Sruvey and criteria
Sruvey, and criteria of snakes in the study area have been shown in table (3).According to the table, we found that the single Leptotyphlopidae is Rare.There is limited information on its distribution and numbers.The two typhlopids are moderate in distribution and numbers.Of the 12 Colubrids, five are widespread, two moderate in distribution and number, three have limited information on distribution and number and three are Rare.The single Atractaspidid is Rare and need special attention in some areas.Of the three elapids, two are moderate in their distribution and need special attention in some areas and the other is Endangered and needs special attention in some areas.Of the six viperids, one is widespread, three moderate in distribution and number, one is moderate in distribution and number and needs special attention in some areas, and one has limited information in distribution and number.From the above, we note that the future of snakes of the area is not clear.There are five rare species and need protection, i.e.Ramphotyphlops braminus, Coluber elegantissimus, Dasypeltis scabra, Telescopus dhara, Atractaspis microlepidota, and one is endangered (Walterinnesia aegyptia).All recorded species were listed by IUCN categories as Lower Rick, Least Concern (IUCN 2005).Burton's carpet viper (1,2) The following are the key taxa that have been included in the updated System Plan for Saudi Arabia.Species were selected by applying the following set of criteria and the numbers in the species lists refer to which criterion or criteria qualify particular organisms for inclusion as "key taxa".1).
Species that are critically endangered, endangered, or vulnerable (globally, regionally, or nationally); taxa which are locally extinct in the wild may be included, provided that there is an NCWCD policy to reintroduce them.2).Species that are endemic to the Arabian Peninsula, the Red Sea, or the Gulf.3).Species of which the conservation of populations within Saudi Arabia is essential to the conservation of the taxon (near-endemics and migrants for which Saudi Arabia represents a critical range).4).Relict species, or subspecies that are of global, regional, or national significance.5).Species of special ecological importance (i.e.fulfilling a vitally important function in an ecosystem such as providing a key habitat for other species, serving as indicator species, etc.).6).Species of significant economic importance.7).Species that serve a "flagship" function (i.e.high-profile species of cultural value, the protection of which will also protect large numbers of other species that share their habitats).
Endemic snakes include Jayakar's sand boa, the elegant racer and Manser's racer, the two carpet vipers, and the native subspecies of the cat snake, cobra, and puff adder.The black desert cobra is a near endemic.The sand boa is essential to the ecosystem of the sand seas, while large predatory snakes such as the Arabian cobra, moila snake, diadem snake, and glossy-bellied racer play important ecological roles.The latter three species are important predators of rodents.The venomous burrowing asp, cobras, carpet vipers, and puff adder are all relentlessly persecuted, and are likely to come under increasing pressure from collection for their venom, which fetches a high price in the pharmaceutical market.

Threats and Conservation Methods
Several factors appear to have signficant effect on the population of snakes.These include commercial exploitation, habitat destruction, environmental pollution, the wrong blief of some people and the bad image of snakes in the mind of most people make all the species victims of humans.Most people will kill any snake they encounter without any hesitation hence they are avoided.
The main threat face the snakes of the area is habitat loss, degradation and fragmentation.Many areas were changed illegally to cultivated areas which cause habitat loss of many species, habitat degradation by changing the area to monotypic area and the decline of biological diversity in different levels including the diversity of fauna, flora and habitats.Those activities cause as well habitat fragmentation and form barriers for the diversion and genetic diversity of these fragile taxa of reptiles of the known poor ability of diversion.Also, the cultivation activities caused extension of the distribution range of some species.Using of fertilizers and pesticides may cause ultimate threat to the reptile fauna generaly of the area and the whole ecosystem as well.Quarrying activities in the area cause habitat loss of many reptile species.

Conservation
Conservation of these taxa should be done by several steps which must be taken by both governementl and non-governemental organizations.These steps are represented in preventing or organizing all reasons of habitat loss and distuction; sustainable utilization of reptile resources; puplic awarness and conservation education to local people about reptiles "snakes " and their importance; captive breeding programmes and protected areas systems; preventing all kinds of commercial exploitation in the adjacent areas; the necessity of consultation of socioeconomic specialists.More systematic research and basic taxonomic work, and more ecological, demographic and behavioural research are needed to help in developing strategies for conserving reptiles and snakes, especially the most endangered species, in addition to more widespread application of scientific knowledge and techniques to conservation.Professionally trained conservationists and biologists in governmental decision-making posts, parks and protected-areas management, and for the growing local nongovernmental conservation organization. (1).

Table 1 :
Co-ordinates: Latitude, longitude and altitude, of the studies area by a GPS

Table ( 2
): Species Composition of terrestrial Snake Fauna of Jazan.Bah dudi aswad, Brahminy blind snake.Distribution: Africa and Asia, but being an introduced species in many parts of the world, it is also found in Australia and the Americas.It is common throughout most of Florida.Usually occurs in urban and agricultural areas.These snakes live underground in ant and termite nests.They are also found under logs, moist leaves and humus in wet forest, dry jungle and even city gardens.The distribution and survival of this group of snakes directly reflects soil humidity and temperature.This is the most widespread snake species in the world, though looking more like a dark, shiny earthworm than a true serpent.Harmless and small (up to 170 millimeters total length).It derives its name from its habit of burrowing in soft moist soil in gardens.
Feeding : Their diet consists of the larvae, eggs, and pupae of ants and termites.Status: Probably widespread and fairly common species.It is classified as Least Concern by IUCN (2005).Genus Typhlops Oppel, 1811 Typhlops vermicularis (Merrem, 1820) Common name: Greek blind snake, Bah doudy Distribution: Southeast Europe, southwest Asia, East to Afghanistan and south to northern Egypt.Distribution in Jazan : Sites (1,2,8,9,10,11,14) Habitat and ecology: Usually occurs in open vegetated sandy terrain often with scattered stones.These snakes live in loose soil, underground in ant and termite nests.They are also found under logs, moist leaves and humus in wet forest, dry jungle and even city gardens.The distribution and survival of this group of snakes directly reflects soil humidity and temperature.Feeding : Their diet consists of larvae and pupae of ants.Status: Rare or uncommon and localized.It is classified as Least Concern by IUCN

Table 3 :
The sruvey and criteria of terrestrial snakes in the study area.