Egypt. J. Exp. Biol. (Zool.), 13(2): 193 – 199 (2017) © The Egyptian Society of Experimental Biology DOI: 10.5455/egysebz.20170717080224 RESEARCH ARTICLE Salwa A.H. H amd i Mona F. Fol Procambrus clarkii (Crustacea: Cambaridae) a biological control agent against four intermediate host snails in Egypt ABSTRACT: Heterophyasis is a chronic parasitic disease INTRODUCTION: infecting fish eaten by man. One of The red swamp crayfish, Procambarus strategies to eradicate parasitic diseases is clarkii, introduced into Egypt, Giza (Manial - the bio-control of its vector snails. Lab Sheiha) at 1980, it has become well experiments and field survey have been established and now supported a small but carried out to investigate the impact and the thriving aquaculture industry (Fishar, 2006). relationship between the exotic crayfish; This crayfish has since dispersed over a Procambarus clarkii, two freshwater snails wide area in Egypt, giving rise to concerns (Pirenella conica and Cleopatra bulimoides) about its ability to disrupt natural ecosystems and other two land snails ( Monacha elsewhere. In addition, P. clarkii may cartusiana and Eobania vermiculata) in adversely affect fin fisheries and has been Egypt. In the Lab, these snails and clover implicated as a pest in rice cultivation Lactuca sativa species were reported to schemes outside of Africa. In addition to its serve as food for freshwater crayfish. The possible impact on species of direct results of the experimental Lab indicated that relevance to human commerce and health, the vector snails; Pirenella conica and the effect of P. clarkii on other non-target Eobania vermiculata were the type of food of organisms and on natural ecosystems in first choice for the crayfish after clover general should be considered as well. followed by Cleopatra bulimoides b ut Crayfish are voracious omnivores and are P. clarkii show no preference against often able to significantly alter the structure Monacha cartusiana as type of food. So, the of natural aquatic communities (Lodge and present investigation indicated that P. clarkii Lorman, 1986; El-Dien et al., 2013 a&b). This can effectively control or eliminate certain might be achieved by direct depredation of freshwater snail species, including those indigenous aquatic invertebrates or involved in the transmission of human vertebrates, or by vigorous consumption of Heterophyasis. Therefore, P. clarkii macrophytes and detritus used by other appeared to act as a biological control agent organisms as food sources or as cover from of snail-transmitted diseases in selected predators, P. clarkii may also serve as a habitats in Egypt. competitor of snails of medical and veterinary significance. On the other hand, a field survey for the exotic freshwater crayfish KEY WORDS: was carried out along the River Nile, Procambarus clarkii; Pirenella conica; introduced accidentally to Egypt during early Cleopatra bulimoides ; Monacha 1980's, by Ibrahim et al. (1995 &1996). They cartusiana; Eobania vermiculata found that the crayfish has established viable populations in the aquatic ecosystems of CORRESPONDENCE: Giza, Cairo and some Nile Delta Governorates. The coefficients of conditional Salwa A.H. H amd i values have indicated suitability of the new Zoology Department, Faculty of Science, environment for this crayfish with regard to Cairo University, Cairo, Egypt feeding condition. They also studied the E-mail: [email protected] feeding behaviour of the exotic crayfish and its prospect in the bio-control of local vector snails and they found that smaller snails Mona F. Fol represent an easier prey to be attacked by Zoology Department, Faculty of Science, the crayfish. Huner and Barr (1991) and Cairo University, Cairo, Egypt McClain et al. (1993) studied the selectivity of this species for combating certain freshwater snails, which are vectors of ARTICLE CODE: 20.01.17 parasitic diseases. Moreover, P. clarkii has been also known for its outstanding feeding ISSN: 2090 - 0511 On Line ISSN: 2090 - 0503 http://my.ejmanager.com/ejebz/ 194 Egypt. J. Exp. Biol. (Zool.), 13(2): 193 – 199 (2017) capacity on some aquatic pest weeds Statistical Analysis: (Groves, 1985; El-Dien et al., 2013 a&b). The obtained results were subjected to Therefore, the present study aimed to analysis of variance (ANOVA) using SPSS measure the feeding activity of P. clarkii Program Ver. 15. against four intermediate host snails Pirenella conica and Cleopatra bulimoides RESULTS AND DISCUSSION: and other two land snails including Monacha Mollusca represented as the second cartusiana and Eobania vermiculata which largest phylum of the animal kingdom, are consumed as the major transmitting forming a major part of the world fauna agent of parasitic diseases, these will be (Lush, 2007). The Gastropod is the only done to consider if P. clarkii represents a class of molluscs to have successfully biological control agent for parasitic diseases invaded land (Smith and Kershaw, 1979). in Eg ypt. They are one of the most diverse groups of animals, both in shape and habit (Mejía and MATERIAL AND METHODS: Zúňiga, 2007). Estimates of total extant Laboratory experiments: species ranged from 40,000 to 100,000 but may be as high as 150,000 (Ponder and Fifty of adult red swamp crayfish Lindberg, 1997), with about 13,000 named Procambarus clarkii (Crustacea: genera for fossil and recent species (Bieler, Cambaridae) of different sizes (3.5 – 6.5 cm 1992). Among gastropods, land snails in length) were collected from different belonged to subclass Pulmonata were one of localities along the River Nile at Giza the most numerous with almost 35,000 Governorate, Egypt. They were transported described species of the world (Solem, alive to the Laboratory of Invertebrates, 1984), mostly found in the tropics, where the Zoology Department, Cairo University and majority remain undiscovered and maintained in glass aquaria (50 x 30 x 20 undescribed, partly because of und er- cm) filled with continuously aerated exploration, and partly because of their dechlorinated tap water which was changed often-minute sizes (Stanisic, 1990; DeWinter, daily. The experiment of the present study 1992 & 1995; Tattersfield, 1994; Cowie et al., designed in the form of, six aquaria filled 1995; Emberton, 1995 a, b, & 1996). Many with 1/6 of their volume with water and ten terrestrial molluscs have become successful specimens of adult P. clarkii, as: world travellers (Robinson, 1999). Most of 1- First aquarium: contained clover these traveling species have had no impact Lactuca sativa species, two species of on humans, but several species have freshwater snails, Pirenella conica and become significant as agricultural pests and Cleopatra bulimoides, and other two as vectors of parasites (Lush, 2007). species of land snails, including Freshwater molluscs have been known Monacha cartusiana and Eobania to play significant roles in the public and vermiculata. veterinary health and thus need to be 2- Second aquarium: contained two scientifically exploring more extensively species of freshwater snails, P. conica (Supian and Ikhwanuddin, 2002). About 100 and C. bulimoides , and other species of freshwater gastropods reported to two sp ecies of land snails, including M. act as intermediate hosts for the diagnostic cartusiana and E. trematode parasites and among vermiculata. Prosobranchs, members of the family Pilidae 3- Third aquarium: contained L. sativa and Thiaridae were recorded to harbour species and two species of freshwater larval trematodes (Subba-Rao, 1993). snails, P. conica and C. bulimoides. 4- Fourth aquarium: contained two Land Mollusca pests are serious species of freshwater snails, P. conica problem, every year; damage involving and C. bulimoides. considerable financial losses inflicted on 5- Fifth aquarium: contains L. sativa cereal, potatoes, vegetables, lettuce, car rots, species and two species of land snails, cabbage, maize, clover as well as other including M. cartusiana and agricultural and horticultural crops. They eat E. vermiculata. leaves, roots and tuber of nearly all 6- Sixth aquarium: contains two sp ecies vegetables, fields crops, ornamental plants of land snails , including M. cartusiana as well as fruits in field, garden and and E. vermiculata. greenhouse. Land snails cause heavy damage, especially to seeds and seedlings of The feeding activity (number of snails cereals and seeds of oil plants. Snails cause eaten per day) and the response of P. clarkii serious economic damages to the leaves and were observed and calculated in the six fruits, which were observed on trunk crops aquaria prepared for about two weeks. The and ornamental plants, as well as apple, capability of the crayfish used to be a citrus, peach, palm and vegetables. Several biological control toward the four snails was studies were carried out on land snails of documented. Egypt included those of El-Okda (1980 & ISSN: 2090 - 0511 On Line ISSN: 2090 - 0503 http://my.ejmanager.com/ejebz/ Hamdi & Foli, Procambrus clarkia: a biological control agent against four intermediate host snails in Egypt 195 1984), El-Okda et al. (1989), El-Deeb et al. organisms. The results shown in table 1 (1996 & 2003), Lokma (2007), Shahawy et al. indicated that the crayfish during the present (2008), Shoieb (2008), and Rady et al. stud y, P. clarkii consumed all species of (2014). plants Lactuca sativa that were added in Food-borne parasitic infections have their aquaria and can be considered an recently been identified as an important essential part of its diet (Groves, 1985; public