Seasonal and Spatial Variations of Meiofauna Communities  in Correlation to Environmental Characteristics in the Organic Shrimp Farms of Tam Giang Commune, Nam Can District, Ca Mau Province

Environmental factors and meiofauna communities in the organic shrimp farms located in Tam Giang commune, Nam Can District, Ca Mau province were investigated in March (dry season), July (transfer season) and November (wet season) of 2015. The results recorded that the environmental factors were not quite optimal for shrimp farming such as the high percentage of TN and TOC and anaerobic condition in sediment. The results were also indicated that DO, TOC and TN showed significant correlation with characteristics of meiofauna communities. Following results were indicated that the meiofauna communities were expressed as the high abundance and slightly biodiversity that is a rich natural food sources for shrimp in the organic shrimp farms ponds. Further more, nematoda dominate numerically in the meiofauna communities. Keywords Biodiversity, Ca Mau, mangroves, meiofauna, organic shrimp farms References [1]. S. Trent, J. Williams, C. Thornton, M. Shanahan, Farming the sea, costing the earth: why we must green the blue revolution (2004).[2]. P. N. Hong, H. T. San, Mangroves of Vietnam 7 (1993) IUCN.[3]. B. T. Nga, Hệ thống rừng-tôm trong phát triển bền vững vùng ven biển đồng bằng sông Cửu Long, Tạp chí Khoa học Trường Đại học Cần Thơ 10 (2008) 6. [4]. Ministry of Agriculture and Rural development, 2016. https://tongcucthuysan.gov.vn/en-us/aquaculture/doc-tin/006222/2016-10-28/ca-mau-set-outs-to-become-viet-nams-largest-shrimp-hub. Truy cập ngày 14/8/2017.[5]. Thai agricutural standard (TAS), Organic marine shrimp farming, Royal Gazette 124 (2007)[6]. T. T. Thai, N. T. My Yen, N. Tho, N. X. Quang, Meiofauna in the mangrove–shrimp farms ponds, ca mau province. Journal of Science and Technology, 55 (2017) 271.[7]. N. Tho, V. N. Ut, R. Merckx, Physico‐chemical characteristics of the improved extensive shrimp farming system in the Mekong Delta of Vietnam, Aquaculture Research 42 (2011) 1600.[8]. R. P. Higgins, H. Thiel, Introduction to the Study of Meiofauna, Smithsonian Institute Press, Washington DC, 1988.[9]. B. C. Coull, Role of meiofauna in estuarine soft‐bottom habitats, Austral Ecology 24 (1999) 327.[10]. N. Majdi, W. Traunspurger, Free-living nematodes in the freshwater food web: a review, Journal of nematology, 47(2015) 28.[11]. C. L. Marte, The Food and Feeding Habit of Penaeus Monodon Fabricius Collected From Makato River, Aklan, Philippines (Decapoda Natantia) 1, Crustaceana 38 (1980) 225.[12]. M. Vincx, Meiofauna in marine and freshwater sediments, In G. S. Hall (Ed.), Methods for the examination of organismal diversity in soils and sediments Wallinfort, UK, 1996[13]. S. Porrello, P. Tomassetti, L. Manzueto, M. G. Finoia, E. Persia, I. Mercatali, P. Stipa, The influence of marine cages on the sediment chemistry in the Western Mediterranean Sea, Aquaculture, 249 (2005) 145.[14]. P. Munsiri, C. E. Boyd, D. Teichert-Coddington, B. F. Hajek, Texture and chemical composition of soils from shrimp ponds near Choluteca, Honduras, Aquaculture International 4 (1996) 157.[15]. C.E. Boyd, Best management practices for water and soil management in shrimp farming. Workshop (2003) in MazatlaŁn, Mexico.[16]. X. N. Quang, A. Vanreusel, N. V. Thanh, N. Smol, Biodiversity of meiofauna in the intertidal Khe Nhan mudflat, Can Gio mangrove forest, Vietnam with special emphasis on free living nematodes, Ocean Science Journal 42 (2007) 135.[17]. X. N. Quang , A. Vanreusel, N. Smol, N. N. Chau, Meiobenthos assemblages in the mekong estuarine system with special focus on free-living marine nematodes, Ocean Science Journal 45 (2010) 213.[18]. S. Vanhove, M. Vincx, D.V. Gansbeke, W. Gijselinck, D. Schram, The meiobenthos of five mangrove vegetation types in Gazi Bay, Kenya, Hydrobiologia 247 (1992) 99.[19]. B. Kondalarao, Distribution of meiobenthic harpacticoid copepods in Gautami-Godavari estuarine system, Indian Journal of Marine Sciences 13 (1984) 80.[20]. A.M.A. Sultan, K. Krishnamurthy, M.J.P. Jeyaseelan,. Energy flows through the benthic ecosystem of the mangroves with special reference to nematodes. Mahasagar Bull. Nat. Inst. Oceanogr., 16 (1983) 317.[21]. A.H. Dye, Vertical and horizontal distribution of meiofauna in mangrove sediments in Transkei, Southern Africa, Estuarine, Coastal and Shelf Science 16 (1983) 591.[22]. D.M. Alongi, Intertidal zonation and seasonality of meiobenthos in tropical mangrove estuaries, Marine Biology 95 (1987) 447.[23]. N. K. Panikkar, Possibilities of further expansion of fish and prawn cultural practices in India, Current Science 21 (1952) 29.[24]. V. C. Chong, A. Sasekumar, Food and feeding habits of the white prawn Penaeus merguiensis, Marine ecology progress series 5 (1981) 185.[25]. Z. A. Ansari, B. S. Ingole, A. H. Abidi, Organic enrichment and benthic fauna–Some ecological consideration, Indian Journal of Geo-Marine Sciences 43 (2014) 554.

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Correlation between Oxygen Demand of Nematode Communities with Dissolved Oxygen in the Organic Shrimp Farming Ponds, Ca Mau Province

VNU Journal of Science Natural Sciences and Technology ◽

10.25073/2588-1140/vnunst.4717 ◽

2018 ◽

Vol 34 (1) ◽

Author(s):

Tran Thanh Thai ◽

Nguyen Le Que Lam ◽

Nguyen Thi My Yen ◽

Ngo Xuan Quang

Keyword(s):

Dissolved Oxygen ◽

Oxygen Demand ◽

Shrimp Farming ◽

Marine Nematodes ◽

Free Living ◽

Nematode Communities ◽

Linnean Society ◽

Oosterschelde Estuary ◽

Marine Shrimp ◽

Shrimp Farms

Dissolved oxygen (DO), total biomass and oxygen demand of nematode communities in the organic shrimp farms located in Tam Giang commune, Nam Can District, Ca Mau province were investigated in three seasons (March-dry, July-transfer and November-wet season) of 2015. The results showed that most of DO values were within permissible limits. However, the frequency distributions of DO values are very compressed at the lower limit of their scale. Total dry biomass varied from 24.77 to 937.04 µgC/10cm2 while oxygen demand ranged from 3467.39 to 64288.50 nlO2/day/10cm2. These values were slightly high when compared to other studies in the world. The following results recorded that the negatively correlation between DO and oxygen demand of nematode communities in the organic shrimp farms. This may well suggest that respiration and metabolic of nematode communities was high and their impact on oxygen dissolved in surface water. Keywords Biomass, dissolved oxygen, Ca Mau, nematode communities, organic shrimp farms, oxgen demand References [1]. P. N. Hong, H. T. San, Mangroves of Vietnam 7 (1993) IUCN.[2]. T. Nga, Hệ thống rừng-tôm trong phát triển bền vững vùng ven biển đồng bằng sông Cửu Long. Tạp chí Khoa học Trường Đại học Cần Thơ 10 (2008) 6.[3]. Thai agricutural standard (TAS), Organic marine shrimp farming, Royal Gazette 124 (2007) Section 78E.[4]. T. T. Thai, N. T. My Yen, N. Tho, N. X. Quang, Meiofauna in the mangrove–shrimp farms ponds, Ca Mau province. Journal of Science and Technology 55(2017) 271.[5]. L. Marte, The Food and Feeding Habit of Penaeus Monodon Fabricius Collected From Makato River, Aklan, Philippines (Decapoda Natantia) 1, Crustaceana 38(1980) 225.[6]. N. Majdi, W. Traunspurger, Free-living nematodes in the freshwater food web: a review, Journal of nematology 47 (2015) 28.[7]. M. C. Austen, Natural nematode communities are useful tools to address ecological and applied questions, Nematology Monographs and Perspectives 2 (2004) 1.[8]. F. Boufahja, H. Beyrem, N. Essid, J. Amorri, E. Mahmoudi, P. Aissa, Morphometry, energetics and diversity of free-living nematodes from coasts of Bizerte lagoon (Tunisia): an ecological meaning, Cahiers de biologie marine 48 (2007) 121.[9]. Ministry of Agriculture and Rural development, 2016. https://tongcucthuysan.gov.vn/en-us/aquaculture/doc-tin/006222/2016-10-28/ca-mau-set-outs-to-become-viet-nams-largest-shrimp-hub. Truy cập ngày 14/8/2017.[10]. M. Vincx, Meiofauna in marine and freshwater sediments, In G. S. Hall (Ed.), Methods for the examination of organismal diversity in soils and sediments Wallinfort, UK, 1996.[11]. A. T. De Grisse, Redescription ou modifications de quelques technique utilis [a] es dan l'etude des n [a] ematodes phytoparasitaires (1969).[12]. R.M. Warwick, H.M. Platt, P.J. Somerfield, Free living marine nematodes. Part III. Monhysterids. The Linnean Society of London and the Estuarine and Coastal Sciences Association, London 1988.[13]. Zullini, The Identification manual for freshwater nematode genera, Lecture book, MSc Nematology Ghent University 2005.[14]. N. V. Thanh, Giun tròn sống tự do Monhysterida, Araeolaimida, Chromadorida, Rhabditida, Enoplida, Mononchida, Dorylaimida. Động vật chí Việt Nam. Hà Nội: Nhà xuât ba̓n khoa học và kỹ thuật, 22, 2007 455. [15]. J. Vanaverbeke, T.N. Bezerra, U. Braeckman, A. De Groote, N. De Meester, T. Deprez, S. Derycke, K. Guilini, F. Hauquier, L. Lins, T. Maria, T. Moens, E. Pape, N. Smol, , M. Taheri, J. Van Campenhout, A. Vanreusel, X. Wu, M. Vincx, (2015)NeMys: World Database of Free-Living Marine Nematodes. Accessed at http://nemys.ugent.be on 2017.[16]. H. M. Platt, R. M. Warwick, Freeliving marine nematodes. Part 1: British enoplids. Pictorial key to world genera and notes for the identification of British species. Cambridge University Press, for the Linnean Society of London and the Estuarine and Brackish-water Sciences Association 1983.[17]. Andrassy I The determination of volume and weight of nematodes, Acta Zoologica 2 (1956) 1.[18]. J. Vanaverbeke, P. M. Arbizu, H. U. Dahms, H. K. Schminke,. The metazoan meiobenthos along a depth gradient in the Arctic Laptev Sea with special attention to nematode communities, Polar Biology 18 (1997) 391.[19]. K. Soetaert, J. Vanaverbeke, C. Heip, P. M. Herman, J. J. Middelburg, A. Sandee, G. Duineveld, Nematode distribution in ocean margin sediments of the Goban Spur (northeast Atlantic) in relation to sediment geochemistry, Deep Sea Research Part I: Oceanographic Research Papers, 44 (1997) 1671.[20]. D.J. Crisp Methods of the study of marine benthos (N.A. Holme & A.D. McIntyre eds), Blackwell Scientific Publications, Oxford, 1971 197. [21]. N. Smol, K. A. Willems, J. C. Govaere, A. J. J. Sandee, Composition, distribution and biomass of meiobenthos in the Oosterschelde estuary (SW Netherlands). In The Oosterschelde Estuary (The Netherlands): a Case-Study of a Changing Ecosystem, Springer Netherlands (1994) 197. [22]. H. Dye, An Ecophysiological Study of the Meiofauna of the Swartkops Estuary, African Zoology 13(1978) 1.[23]. Van Damme, R. Herman, Y. Sharma, M. Holvoet, P. Martens, Benthic studies of the Southern Bight of the North Sea and its adjacent continental estuaries, Progress Report II. Fluctuations of the meiobenthic communities in the Westerschelde estuary. ICES. CM/L, 23 (1980) 131.[24]. Q. X. Ngo, C. Nguyen Ngoc, A. Vanreusel, Nematode morphometry and biomass patterns in relation to community characteristics and environmental variables in the Mekong Delta, Vietnam, Raffles Bulletin of Zoology 62 (2014) 501.[25]. J. M. Whetstone, G. D. Treece, C. L. Browdy, A. D. Stokes, Opportunities and constraints in marine shrimp farming, South Regional Aquaculture Center 2002.

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Probiotics as Antiviral Agents in Shrimp Aquaculture

Journal of Pathogens ◽

10.1155/2013/424123 ◽

2013 ◽

Vol 2013 ◽

pp. 1-13 ◽

Cited By ~ 55

Author(s):

Bestha Lakshmi ◽

Buddolla Viswanath ◽

D. V. R. Sai Gopal

Keyword(s):

Antimicrobial Agents ◽

Antiviral Agents ◽

Shrimp Farming ◽

Shrimp Aquaculture ◽

Viral Diseases ◽

Human Consumption ◽

Treatment And Prevention ◽

Power Enhancement ◽

Shrimp Farms ◽

Criteria For Selection

Shrimp farming is an aquaculture business for the cultivation of marine shrimps or prawns for human consumption and is now considered as a major economic and food production sector as it is an increasingly important source of protein available for human consumption. Intensification of shrimp farming had led to the development of a number of diseases, which resulted in the excessive use of antimicrobial agents, which is finally responsible for many adverse effects. Currently, probiotics are chosen as the best alternatives to these antimicrobial agents and they act as natural immune enhancers, which provoke the disease resistance in shrimp farm. Viral diseases stand as the major constraint causing an enormous loss in the production in shrimp farms. Probiotics besides being beneficial bacteria also possess antiviral activity. Exploitation of these probiotics in treatment and prevention of viral diseases in shrimp aquaculture is a novel and efficient method. This review discusses the benefits of probiotics and their criteria for selection in shrimp aquaculture and their role in immune power enhancement towards viral diseases.

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Floating nurseries? Scyphozoan jellyfish, their food and their rich symbiotic fauna in a tropical estuary

10.7287/peerj.preprints.26497 ◽

2018 ◽

Author(s):

José M Riascos ◽

Willington Aguirre ◽

Charlotte Hopfe ◽

Diego Morales ◽

Ángela Navarrete ◽

...

Keyword(s):

Surface Waters ◽

The Body ◽

Food Sources ◽

Gut Contents ◽

Estuarine System ◽

Symbiotic Association ◽

Bell Diameter ◽

Associated Fauna ◽

Size Relationship ◽

Scyphozoan Jellyfish

The anthropogenic modification of basal trophic pathways is seemingly prompting the increase of jellyfish populations at the expense of planktivorous fishes. However, gross generalizations are often made because the most basic aspects of trophic ecology and the diverse interactions of jellyfish with fishes remain poorly described. Here we inquire on the dynamics of food consumption of the medusoid stage of the scyphozoan jellyfish Stomolophus meleagris and characterize the traits and diversity of its symbiotic community. S. meleagris and their associated fauna were sampled in surface waters between November 2015 and April 2017 in Málaga Bay, an estuarine system at the Colombian Pacific. Stomach contents of medusae were examined and changes in prey composition and abundance over time analysed using a multivariate approach. The associated fauna was identified and the relationship between the size of medusae and the size their symbionts tested using least-square fitting procedures. The presence of S. meleagris medusa in surface waters was seasonal. The gut contents analysis revealed that algae, copepods and fish early life stages were the more abundant items, and PERMANOVA analysis showed that the diet differed within the seasons (P(perm)=0.001) but not between seasons (P(perm)=0.134). The majority of the collected medusae (50.4 %) were associated to individuals of 11 symbiotic species, 95.3% of them fishes, 3.1% crustaceans and 1.6% molluscs. Thereby, this study reports 10 previously unknown associations. The bell diameter of S. meleagris was positively related to the body sizes of their symbionts. However, a stronger fit was observed when the size relationship between S. meleagris and the fish Hemicaranx zelotes was modelled. The ocurrence of S. meleagris was highly seasonal, and the observed patterns of mean body size through the seasons suggested the arrival of adult medusae to the estuary from adjacent waters. The diet of S. meleagris in the study area showed differences with previous reports, chiefly because of the consistent abundance of algae that are seemingly ingested but not digested. The low number of zooplanktonic items in gut contents suggest the contribution of alternative food sources not easily identifiable. The observed changes in the composition of food in the guts probably reflect seasonal changes in the availability of prey items. The regular pattern in the distribution of symbionts among medusae (a single symbiont per host) and the positive host-symbiont size relationship reflects antagonistic intraspecific and interspecific behaviour of the symbiont. This strongly suggest that medusa represent an “economically defendable resource” that potentially increases the survival and recruitment of the symbionts to the adult population. We argue that, if this outcome of the symbiotic association can be proven, scyphozoan jellyfish can be regarded as floating nurseries.

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The THE ECOLOGICAL QUALITY STATUS OF THE ORGANIC SHRIMP FARMING PONDS: USE OF A NEW BIOTIC INDICES

VNU Journal of Science Natural Sciences and Technology ◽

10.25073/2588-1140/vnunst.4733 ◽

2018 ◽

Vol 34 (2) ◽

Author(s):

Trần Thành Thái

Keyword(s):

Farming Systems ◽

Shrimp Farming ◽

Food Sources ◽

Biotic Index ◽

Natural Food ◽

Ecological Quality ◽

Wet Season ◽

Tropical Regions ◽

Ecological Quality Status ◽

Quality Status

In spite of the development and widespread dissemination of the model organic shrimp farming systems, the biological communities in the organic shrimp farming ponds have still very limited. Therefore, we conducted a field survey for macrobenthic communities (MC) of the Tam Giang‘s organic shrimp farming ponds (TGOSFP) located in Tam Giang commune, Nam Can district, Ca Mau province during three seasons in 2015 (March - dry, July - transfer and November - wet season). The results indicated that the MC have characterized by high density and slightly diversity that is a rich natural food sources for shrimp in the TGOSFP. Further more, the present study is a first attempt to use of new indices (AMBI - AZTI’s Marine Biotic Index) on MC for determining the ecological quality status of sediment (EcoQ) in the TGOSFP. The following results were also recorded with an undisturbed and slightly disturbed EcoQ in the TGOSFP and the general EcoQ would likely be improved between three seasons. The success of AMBI for detecting EcoQ in Vietnam is specific to this study, but AMBI was likely to improved, in particular tropical regions.

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Floating nurseries? Scyphozoan jellyfish, their food and their rich symbiotic fauna in a tropical estuary

10.7287/peerj.preprints.26497v1 ◽

2018 ◽

Author(s):

José M Riascos ◽

Willington Aguirre ◽

Charlotte Hopfe ◽

Diego Morales ◽

Ángela Navarrete ◽

...

Keyword(s):

Surface Waters ◽

The Body ◽

Food Sources ◽

Gut Contents ◽

Estuarine System ◽

Symbiotic Association ◽

Bell Diameter ◽

Associated Fauna ◽

Size Relationship ◽

Scyphozoan Jellyfish

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Diagnóstico do Licenciamento Ambiental da Carcinicultura no Estado do Rio Grande do Norte, Brasil

Revista Brasileira de Geografia Física ◽

10.26848/rbgf.v12.7.p2392-2406 ◽

2020 ◽

Vol 12 (7) ◽

pp. 2392

Author(s):

Iáskara Michelly De Medeiros Silveira ◽

Daniele Bezerra dos Santos ◽

Franklin Roberto da Costa ◽

Rodrigo Herico Rodrigues de Melo Soares ◽

Tarcisio Augusto Gonçalves Junior ◽

...

Keyword(s):

Sustainable Development ◽

Rio Grande ◽

Environmental Studies ◽

Environmental Problems ◽

The State ◽

Shrimp Farming ◽

Southern Coast ◽

Environmental Licensing ◽

Development And Environment ◽

Shrimp Farms

Em função do crescimento desordenado da carcinicultura no Nordeste do Brasil, nesta pesquisa foi realizado um levantamento dos licenciamentos ambientais voltados à carcinicultura do Estado do Rio Grande do Norte, ao longo da década de 2005 a 2015, referente ao número de empreendimentos licenciados por ano, porte dos empreendimentos por tipos de licenças outorgadas e regiões com maior densidade de fazendas de carcinicultura. A pesquisa foi realizada através de avaliação documental, com dados cedidos pelo Instituto de Desenvolvimento Sustentável e Meio Ambiente (IDEMA, 2016), e embasado nas legislações nacionais e estaduais pertinentes à área de estudo. No total, foram analisadas 698 licenças, sendo a maioria das fazendas de porte médio e solicitantes de licenças de operação, havendo uma maior concentração de empreendimentos de diferentes portes no litoral Sul do estado. Evidenciou-se uma grande quantidade de fazendas (64,18%) com solicitação de licenças atrasadas, além da constatação de que o maior número de licenças foi expedido no período em que mais ocorreram problemas de ordem ambiental e econômica na atividade. Environmental Licensing diagnosis of Srimp farming in the state of Rio Grande do Norte, BrazilA b s t r a c tIn this article, a survey was made regarding the environmental licensing of shrimp farming in Rio Grande do Norte, during the decade between 2005 to 2015, in relation to the number of enterprises licensed per year, size of enterprises by type of licenses granted and regions with higher density of shrimp farms. The research was done through documentary evaluation, with data provided by the Institute for Sustainable Development and Environment (IDEMA). A total of 698 licenses were identified, with the majority of medium-sized farms and applicants for operating licenses, with a higher concentration of micro, small, medium and large ports in the southern coast of the state. A large number of farms with a request for delayed licenses (64,18%) were evidenced, in addition to the finding that the highest number of licenses was issued in the period in which there were more economic and environmental problems in the activity.Keywords: Environmental studies. Aquaculture. Shrimp. Environmental vulnerability.

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Feeding ecology of free-living nematodes.

Ecology of freshwater nematodes ◽

10.1079/9781789243635.0006 ◽

2021 ◽

pp. 185-215

Author(s):

Nabil Majdi ◽

Tom Moens ◽

Walter Traunspurger

Keyword(s):

Feeding Ecology ◽

Trophic Interactions ◽

Feeding Habits ◽

Food Sources ◽

Environmental Constraints ◽

Feeding Rates ◽

Feeding Selectivity ◽

Free Living ◽

Aquatic Nematodes ◽

Food Recognition

Abstract This chapter provides overview of the feeding habits and food sources of aquatic nematodes. The environmental constraints on feeding, food recognition, and feeding selectivity are also addressed, together with the complex, indirect trophic interactions between nematodes and their microbial prey. To raise awareness of the inherent methodological and/or interpretational problems in studies of nematode feeding ecology, the chapter ends with a brief look at the methods that have been adapted to quantify feeding rates in nematodes.

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Food Habits and Diet Relationship in the Redbelly Tilapia (Tilapia zillii) and Guenther’s Mouthbrooder (Chromidotilapia guntheri) from an Abandoned Gold Mine Reservoir, Southwestern Nigeria

Notulae Scientia Biologicae ◽

10.15835/nsb10210254 ◽

2018 ◽

Vol 10 (2) ◽

pp. 148-155

Author(s):

Olusola Olaniyi KOMOLAFE ◽

Timothy Olalekan AMOO ◽

Michael Olufemi AWODIRAN

Keyword(s):

Feeding Habits ◽

Stomach Contents ◽

Food Sources ◽

Gold Mine ◽

Southwestern Nigeria ◽

Food Items ◽

Tilapia Zillii ◽

Gill Net ◽

Food And Feeding ◽

Index Value

The food and feeding habits of the redbelly Tilapia (Tilapia zillii) and Guenther’s mouthbrooder (Chromidotilapia guntheri) were investigated in an abandoned gold mine reservoir at Igun from June 2013 to May 2014. Using a cast net and gill-net fishing gears, 370 fish individuals were caught and their stomach contents were analysed by using the frequency of occurrence and numerical methods. Tilapia zillii comprised 53.78% (199 individuals), while Chromidotilapia guntheri covered up the remaining percentage (46.22%) which is made up of 171 individuals. Food items in the stomachs of T. zillii individuals predominantly consisted of detritus, mud and algae (77.97%), while those in C. guntheri individuals mostly consisted fish remains, detritus and algae (81.67%). T. zillii exploited more food items (23 of 27) as compared to C. guntheri (17 of 27). The Schoener’s index value for the species was 0.65. The study showed that T. zillii and C. guntheri exhibited benthopelagic exploitation and are mainly herbivorous and omnivorous respectively based on the food items observed in the stomach contents of these species. The fish species fed on related food items as confirmed by Schoener’s overlap index (0.65), suggesting that there was overlap in the dietary requirements of the two species. This index value, however, was probably not an indication of competition for food between these two species because they exploited abundant food sources.

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