PARASITE OF WALL GECKO (Hemidactylus frenatus) IN SELECTED AREAS OF AKWA IBOM STATE, NIGERIA
In order to identify the parasites of wall geckos (Hemidactylus frenatus) in Uyo and Etinan Local Government Areas, a total of sixty (60) wall geckos were caught in selected households within Uyo and Etinan L.G.As from September to December 2015. These were done under bright electric bulbs using sweep net at night, at the back of calendars on the walls during the day time. The ectoparasites were examined using hand lens, while the examination of endoparasite was done using chi-square (X2) distribution. Also, for the examination of the ectoparasite, the skin of the gecko was gently scrapped using scalpel and placed on a petri-dish containing saturated sodium chloride (NaCl), after which the scraps were collected on clean slides and viewed using X10 objectives of the light microscope for identification. The endoparasites was examine using floatation method. Out of sixty (60) Hemidactylus frenatus examined, 33 (55%) were positive for ectoparasites infestations and Ixodes sp. recorded the highest prevalence of 21 (63.6%) than Trombicula sp. 12 (36.4%). 39 (65%) were positive for endoparasites infestation and Parapharyngodon sp. recorded the highest prevalence of 33(84. 6%) than Oochoristica sp. (63.3%). The males had the highest prevalence (68.9%) than the females (18.2%). The assessment of the parasitic loads in the two study areas varied with Uyo, L.G.A having the highest prevalence of 24 (68.6%) while Etinan L.G.A had 15 (60%) respectively.
House Gecko (Hemidactylus frenatus commonly known as Asian House gecko, Pacific house gecko, house lizard, spiny-tailed house gecko, chichak/cheechak (Indonesian), bridled house gecko, belongs to the family Gekkonidae, Infra-order Gekkota. The genus Hemidactylus consists of 124 named species distributed across all tropical and subtropical regions (Brogard, 2005; Vetz, 2013). They range in size from 1.6cm to 60cm in length. Unlike Lizards, geckos are usually nocturnal and great climbers. They come in various patterns and colour and are among the most lizards in the world (Piper, 2007). According to Rogner (1992), a medium sized genus of about 20 species is found predominantly in Africa, the Canary Island and the middle East, but with a few spp. in Europe and tropical America.
Male geckos are generally longer and heavier than female and have a wider jaw scalation is uniform with distinctive, slightly enlarged spines scattered over the back and arranged in bands around the tail. Colour varies from matt grey or light brown through beige, to a greenish iridescence. The underside is whitish (Animal Life Resource, 2008). Their faeces are often considered to be a nuisance and can cause salmonella infection when ingested (Callaway et al., 2011).
According to Krysko et al. (2003), Geckos have incubation period of 45 – 70 days, 2 eggs per clutch; oviposition frequency of 21 – 28 days; 1 year sexual maturity; and approximately 5 years life span. Mating involves a short courtship, during which the male repeatedly touches the female with its snout. It may also bitehold her neck. Three to four weeks after mating, 2 hard-shelled eggs are laid, partially fixed to a solid surface. Successful incubation requires a temperature of atleast 280C. Breeding occurs throughout the year in tropical areas, but is seasonal in cooler climate (Krysko et al., 2003; Wilson, 2006). Females can store sperm for up to a year, a feature that probably assists the species invasion success (Yamamoto and Ota, 2006).
Hemidactylus frenatus is territorial with a social hierarchy (Frenkel, 2006). Geckos are unique among lizards in vocalization, making chirping sounds in social interactions with other geckos. The house gecko is a native of South Eastern Asia and Northern parts of Africa. They have been introduced to many other countries including Nigeria (Cook R. A. 1990; Wilson, 2006).
House lizard is a generalist predator and will eat virtually any insect or spider it can capture and swallow (Wilson, 2006). A study of stomach contents from a population of house gecko in Brisbane identified prey items from seven orders of insects (Blattodea, Hymenoptera, Homoptera, Lepidoptera, Diptera, Coleoptera, and Aranaea) (Newbery and Jones, 2007). House gecko consumes mosquitos and the adults larvae of papers wasps (Wilson, 2006).
Asian house gecko is most abundant in urban environments, often seen on the walls of houses and windows at night and in gardens, hence the common name ‘house gecko’. However, it can survive away from buildings, albeit in generally on trees, in open fields, rocky and forested areas, coconut palm trunks, under rotting logs, and among dense, low ground-cover such as Ipomea and canavalia (Greer, 2006).
Microscopic satae on the sub-digital lamella increases the climbing ability of the species (Russel, 2002; Pianka and Sweet, 2005), allowing it to move and forage freely on the large, structurally simple, vertical and inveted surfaces (such as walls and windows) often illuminated by external light sources. Predators of Pacific house gecko include; cats, snakes, rats, dogs, large spiders, birds, preying mantids, and large lizards (Barquero and Hilje, 2005; Greer, 2006).
Like all vertebrates, Geckos are susceptible to parasitism in their niche. They are infested by ticks, mites and helminthes. Parasites include; Nematodes (round worms), Apicomplexans (Protozoa), Cestodes (tapeworms), Pentastomes (tongue worms), Trematodes (flukes) (Domrow R. and Kennedy C., 1980; Greer, 2006). Direct and indirect contacts with geckos clearly represent a substantial risk to human health. This however, informs this study to survey the parasites of wall geckos in the study areas.
1.1 Aims and Objectives of the Study
– To identify parasites of wall gecko.
– To determine the prevalence and intensity of infection in wall gecko (H. frenatus) in Uyo and Etinan Local Government Areas.
– To evaluate the parasitic risk of geckos to human beings in the study areas.