Food and Feeding Habits of Protopterus Annectens (Owen ...

PAT December 2010; 6 (2): 69-74 ISSN: 0794-5213Online copy available atwww.patnsukjournal.net/currentissuePublication of Nasarawa State University, KeffiFood and Feeding Habits of Protopterus Annectens (Owen) (Lungfish) at Idah Areaof River Niger, NigeriaADEYEMI, Samuel OlusegunDepartment of Biological Sciences, Kogi State University, P.M.B. 1008, AnyigbaE-mail: sadeyemi2003@yahoo.comTel: +2348062221968Received 30 th July, 2010, Accepted 19 th December, 2010AbstractThe food and feeding adaptations of Protopterus annectens in Idah area ofRiver, Kogi State were studied. A total of 62 fish samples of were obtainedfrom Egah market, Idah area of river Niger, Kogi State. The samples werepurchased weekly from the fishermen from July to December 2007, examinedfresh and transported into the Biological Sciences Laboratory for analysis.Each stomach was split open and the contents emptied into a Petri-dish. Thecontents were then observed under a monocular microscope and the stomachcontents analyzed using frequency of occurrence and numerical methods. Theresult showed that P. annectens is an omnivore feeding on other fish,sand/mud, insect parts, plant parts, crustaceans, cyst, worms, detritus andsome unidentified food items. The stomach fullness during the period of studycould be attributed to food abundance and good feeding habit.Keywords: Lungfish, stomach content, feeding habit.IntroductionFish must exploit food in aquatic environment and the adaptation for these is source ofsome morphological traits related to feeding. Understanding the relationship betweenbody structures and fish diet could be important for predicting the diet of, how they feedand the mechanics of feeding. sStudies on stomach composition could provide usefulinformation in positioning of the fishes in a food web in their environment and informulating management strategy options in multi species fisher (Joseph and Djama,1994). Pius and Benedicta (2002) reported the use of stomach content results to reduceintra and inter specific competition for ecological niche. The data on stomachcomposition of fish is vital in providing models of stomach content dynamics (Palmoreet al 1997).Protopterus annectens commonly known as African lungfish is the only specie ofprimitive family Lepidosirenidae found in West African fresh waters (Reed et al 1967).

PAT 2010; 6 (2): 69-74 ISSN: 0794-5213;. Adeyemi, S. O: Food and Feeding Habits of Protopterus Annectens … 71Stomach Contents Analysis: Each stomach was split open and the contents emptiedinto a Petri-dish. The contents were then observed under a monocular microscope. Thefood materials were identified with the aid of keys provided by Needham and Needham(1962) and Mellanby (1975).The stomach contents were analyzed by frequency of occurrence method as describedby Hynes (1950). Each food item was identified and number of stomachs in which eachfood occurred was counted and expressed as a percentage of stomach containing food.The method showed the proportion of individuals eating a particular food item in aspecies. The occurrence of each food item was expressed as a percentage of all stomachwith food. That is, P = (b/a) x 100.Where, a = Total number of fish examined with food in the stomach; b = Number offish containing a particular food item; P = Percentage of occurrence of each food item.Data Analysis: The relationship between the fish Total length (TL) and Gut length(GL) was computed using a linear regression model.GL = a + b TLWhere GL is Gut length (cm); TL is fish total length (cm); a is constant; b is exponent.Result and DiscussionFeeding Adaptations: The mouth of P. annectens is relatively small and terminal forfeeding on smaller food substances in mid and open water, hence predator or prey onplanktons (Reed et al 1967; Holden and Reed, 1972).The teeth found in the species greatly and relatively to omnivorous food habits and itsprimitive compared to those found in the other species (Reed et al., 1967). The presenceof razor-like bony ridge teeth (fusiform teeth) indicates that ability of P. annectens tocrack hard food substances like seeds and fruits (Reed et al., 1967).Stomach Fullness: Table 1 shows the stomach fullness of samples analyzed. Twentyfour percent (24.19%) of the sample had empty stomach while 75.8% had full stomach.This may suggest earlier stoning of the fish samples immediately after capture andactive fishing methods employed. Similarly higher occurrence of non-empty stomachwere due to good feeding strategy of species and food abundance in most part of theyear (Fagade, 1978). The result of the higher fullness of stomach during the period ofthis work (August to November), more so, the availability of food material may be thereason for higher percentage of full stomach. The result is in line with the findings ofShinkafi and Ipinjolu (2001) on the occurrence higher percentage of Synodontis clariaswith food in July and August (Rainy season) when food was available.

PAT 2010; 6 (2): 69-74 ISSN: 0794-5213;. Adeyemi, S. O: Food and Feeding Habits of Protopterus Annectens … 72Table 1: Stomach fullness of Protopterus annectens at Idah area of River Niger,NigeriaSex 0/4(n=14)4/4(n=9)¾(n=16)½(n=14)¼(n=9)Subtotal Percentage(%) totalAF 0.36 0.22 0.19 0.14 0.43 1.34 26.91AM 0.21 0.33 0.25 0.21 0.14 1.14 22.89Grandtotal0.99 0.99 1.00 1.00 1.00 4.98 100%Food Items: The frequency and numerical method result of the stomach of P.annectens is shown in Table 2. The major categories of food items found in the stomachby % frequency of occurrence includes; plant parts (24.16%), fish part (6.12%),sand/mud (33.07%), crustaceans (8.57%), insect parts (8.13%), worms (0.22%), cyst(0.11%), detritus (6.12%) and unidentified items (13.47%). While numerical methodhad the following %, plant parts (32.42%), fish part (16.35%), sand/mud (32.21%),crustaceans (4.90%), insect parts (2.79%), worms (0.73%), cyst (0.15%), detritus(4.15%), unidentified items (6.30%). Analysis of variance showed that there was nosignificant difference (P>0.05) in the stomach content based on the method used. Oniyeet al., (2006) had earlier reported the presence of insect, fish part, mollusks and seeds inthe stomach of P. annectens from Jachi dam. On the contrary Reed et al., (1967) andreported the fish to feed on frogs, mollusk, fish and seeds and concluded that the fish isa carnivore. Fish species tend to have preference for some items they consume as foodOfujekwu and Ejike (1992) reported that there is preference for a particular foodorganism in the diet of most species.Table 2: Stomach contents of Protopterus annectens using frequency of occurrenceand numerical methodsFood items% frequency of occurrence % Numerical methodPlant parts 24.16 32.42Fish parts 6.12 16.35Sand/mud 33.07 32.21Crustaceans 8.57 4.90Insect part 8.13 2.79Worms 0.22 0.73Cyst 0.11 0.15Detritus 6.12 4.15Unidentified items 13.47 6.30

PAT 2010; 6 (2): 69-74 ISSN: 0794-5213;. Adeyemi, S. O: Food and Feeding Habits of Protopterus Annectens … 73The result obtained suggest that the species in an omnivore feeding more on plant andanimal materials, sand grains and detrital matter. This deduction tallied with thefindings of Holden and Reed, (1972) who report cyst, fish parts, benthic worms, insectand detrital matter as dominant food items in the stomach of ancient Protopterusspecies. The result of this study showed that animal food material had higheroccurrences during the study period. This may suggest diversify food habit of thespecies because it possesses well equipped canal and bony-ridge teeth for manipulatinganimal substances (Malami et al., 2004). The non-empty stomach could be attributed tofood abundance and good feeding habits.ConclusionThe presence of primitive feeding adaptive features in P. annectens suggest themodification of structural trait to suit omnivorous feeding habit. The stomach fullnessduring the period of study could be attributed to food abundance and good feedinghabits. The food preference of P. annectens in natural ecosystem as revealed by thestomach content may be useful in multispecies fishery management as well as aquafeed.ReferencesFagade, S.O. (1978). The food and feeding habits of Tilapia species from the Lagoslagoon. Journal of Fish Biology, 3:151 – 156.Needham, P.R. and J.G. Needham (1962). A guide to the study of freshwater biology. 5 thedition Holden Day Inc. LondonHolden, M. and W. Reed (1972). West African Fresh water Fishes West African NatureBook Longman Publications, London.Hynes, H.B.N. (1950). The food of fresh water Stickle backs (Gasterosteus acculeatusand Pygoteus pungistis) with review of methods used in studies of the food offishes. Journal of Animal Ecology 19:36 – 58Ipinjolu, J.K., G.Z. Malami, W.A. Hassan and I. Magawata (2004). Gut systems ofsome fresh water fish species in River Rima Northern Nigeria. A paperpresented at the 2004 Annual Conference of Zoological Society of Nigeria, heldat Institute of Development Research, Ahmadu Bello University, Zaria.Joseph, Y.J. and T. Djama, (1994). Food habits of two sciaenid fish speciesPseudotolithus and Pseudotolithus senegalensis off Cameroon. NAGA ICLARMQuarterly Volume 2:pp 40 – 41.Lagler, K.F., Bardach, J.E., Miller, R.R. and May Passino, D.R. (1977). Ichthyology. 2 ndEdition. Wiley and Sons Inc. printed in USA pp 129 – 163

PAT 2010; 6 (2): 69-74 ISSN: 0794-5213;. Adeyemi, S. O: Food and Feeding Habits of Protopterus Annectens … 74Malami, G.Z., J.K. Ipinjolu, W.A. Hassan and I. Yaro (2004). Feeding Adaptations often fish species in River Rima North Western Nigeria. A paper presented at the2004 Annual Conference of Zoological Society of Nigeria, held at Institute ofDevelopment Research, Ahmadu Bello University, Zaria pp1 – 13Mellanby, H. (1975). Animal Life in Freshwater. A guide to Freshwater Invertebrates6 th ed. Chapman and Hall, LondonOfojekwum, P.C. and Ejike, C. (1992). Food composition and feeding habits ofOreochromis niloticus in Panyam Fish Farm, Nigeria. Journal of AquaticScience, 7:13 – 17Olatunde, A.A. (1979). The food and feeding habits of Eutropius niloticus (Ruppel),Family Schilbeidae (Osteichthys:Siluriforms) in Lake Kainji. Hydrobiologia,57:197 – 203Oniye, J.S., Adebote, D.E., Usma, S.K. and Makpo, J.K. (2006). Some aspect of thebiology of Protopterus annectens in Jachi Dam near Katsina, Katsina StateNigeria. Journal of Fisheries and Aquatic Science, 1(2):136 – 141,2006.Palmores, M.L.D, L.R. Garces, Q.P. Sia II and M.J.M. Vega (1991). Diet compositionand daily ration estimates of selected trawl caught fishes in San Miguel bay,Philippines NAGA, the ICLARM Quarterly Vol. 2 pp 35 – 40.Pius, M.O. and O.O. Benedicta (2002). Food and feeding inter-relationship. Apreliminary indicator to the formulation of the feed of some Tilapine fishes.Tropical Journal of Animal Science, 5(1):35 – 41Reed, W., J. Burchard, A.J. Hopson, J. Jennes, I. Yaro (1967). Fish and Fisheries ofNorthern Nigeria. 1 st Ed. Ministry of Agriculture, Northern Nigeria. 226pShinkafi, B.A. and Ipinjolu, J.K. (2001). Food and feeding habits of catfish, Synodontisclarias (Linneaus) in River Rima, Nigeria. Journal of Agriculture and Environment2(1):104 - 120