Greener Journal of Biological Sciences

Vol. 9(2), pp. 59-64, 2019

ISSN: 2276-7762

Copyright ©2019, the copyright of this article is retained by the author(s)

https://gjournals.org/GJBS

 

 

Description: C:\Users\user\Pictures\Journal Logos\GJBS Logo.jpg

 

 

 

 

Dietary Composition and Macroinvertebrates Selectivity of Ethmalosa fimbriata in Forcados River Estuary, Delta State, Nigeria

 

 

*Ogidiaka, E.; Atadiose, J.; Bekederemo, B.O.

 

 

*1Department of Science and Technology, Fisheries and Fisheries Technology Option, Delta State School of Marine Technology, P.M.B. 1060 Warri, Burutu, Delta State, Nigeria.

 

 

 

 

ARTICLE INFO

ABSTRACT

 

Article No.: 051920074

Type: Research

 

 

Background and Objective: published information on the food and feeding habits of the clupeid, E. fimbriata in Forcados river estuary which is a dominant and important economic fish species in the region is scare. This study would therefore provide vital information that could be used by other researchers for future studies. Materials and Methods: Stomach content was analysed using frequency of occurrence (Fi) and volumetric method. For food selectivity estimations the Ivlev index was adopted. Variation in the amount of food consumed by fish in relation to body mass was calculated using gastrosomatic index (GSI). The Gut repletion index (GRI) was calculated according to Ekpo et al. (2014). Results: Of these 1095 (96.73%) had food items while 38 (3.27%) had empty stomachs indicating that this species were active feeders. High GSI and GRI values were recorded. The species fed predominantly on Microcystis and accounted for 24.99% (the highest percentage) of the food items by percent occurrence frequency while Macrobrachium sp had the highest by percent volume of food (42.3%). The consumption of food items recorded in this study did not follow any seasonal pattern. The number of empty stomach was generally higher in the rainy season months than the dry season. The macroinvertebrate positively selected by E. fimbriata was Callinectes sp. Conclusion: The study indicated that E. fimbriata fed on phytoplankton as a major diet.

 

*Corresponding Author

Ogidiaka, E.

E-mail: efeogis@ yahoo. com

Phone: +234 8063777441

 

Keywords: Food and feeding pattern; Ethmalosa  fimbriata; Forcados river estuary; Delta State; Fish.

 

 

 

 

 

 


INTRODUCTION

 

Studies on the dietary analysis of a fish species is fundamental to a successful fisheries management aimed at fish capture and culture [1]. However, published information on the food and feeding habits of the clupeid, Ethmalosa  fimbriata in Forcados river estuary which is a dominant and important economic fish species in the region is scare. Previous works on this clupeid in Nigeria include those of [2,3,4,5,6,7,8].This study would therefore provide vital information that could be used by other researchers for future studies.

E. fimbriata has a superior mouth, a large head and a deep and compressed body [9]. According to 9, this species is black bluish green in colour with silver sides and a yellow anal and caudal fin. The upper portion of the head is golden and possesses a botch behind its operculum. It also has a deeply forked operculum and is usually abundant from October to November in this water body. The fish is highly eaten by many people in Nigeria especially the coastal dwellers, providing basic animal protein to the populace.

E. fimbriata feeds by filtering planktons [7] and sometimes fish larva [9]. The food and feeding habits of fish in their natural habitats enhances the understanding of the abundance, distribution, growth and productivity of an organisms [2] Data on the food and feeding habits of a fish can provide information on the status of an aquatic ecosystem.

 

 

MATERIALS AND METHODS

 

The study area

 

The study was carried out in Forcados River estuary, between Burutu and Forcados in the Niger Delta Area of Nigeria (latitude 5º 21ꞌ - 50 35ꞌ N and longitude 5º 31ꞌ - 50 51ꞌ E). The area is known to have both rainy and dry seasons. The dry season starts from November to April while the rainy season strerches from May to October [10]. The vegetation covers include Eichhornia crassippes, Pistia, Pennisetum purpureum, Nymphaea spp, Trapa spp, Ceratophyllum spp. Human activities here include offloading and selling of goods and petroleum products, jetty operations, boat movement, laundering and washing of boats, log movement, dumping of organic and inorganic waste, bathing and swimming. 

 

Collection and preservation of fish samples

 

Samples were collected monthly between April 2012 and March 2014 from artisanal fisher folks and taken to the laboratory for analysis. 1133 stomachs of E. fimbriata were analysed. The fish were sorted and identified to the species level using the keys of [11,12,13,9].

 

 

 

Stomach content analysis

 

The abdomen of some economic fish was slit open and the content placed in a petri dish. The aggregate of food items was dispersed in water. Aliquot samples were taken with a dropping pipette from a stack and placed in a small petri dish, spread out evenly and subjected to stereomicroscopic examination (10 - 100x). Large food organisms such as prawns, bivalve mollusc and fish were counted directly whenever encountered. The remaining microscopic organisms were counted using a binocular zoom microscope, and the number of food items present was counted directly. Stomach content was analysed using the occurrence frequency (Fi) method and volumetric analysis index [14,15,16,17,18]

 

Occurrence Frequency (Fi) Method

 

The number of stomachs in which each food items occurred was noted and expressed as a percentage of the entire stomachs examined. This method gives the proportion of the population of fish that feeds on a particular food item.

 

Fi = 100ni/n

 

Description;

 

 = occurrence frequency of food i

 = number of food i

 = total number of a digestive tract containing food

 

Volumetric Analysis Index uses the formula:

 

 

Where:

 

: Volumetric Analysis Index of the i food item in the samples;

: multiplication constant to obtain the percentage;

: mean of the points ascribed for the i food items.

Using the Index of Preponderance the main food that was eaten was determined, an integration of occurrence frequency method and volumetric analysis index. Preponderance index was determined following [19]:

 

Description:

 

×100

 

Vi = percent volume of food

 = percent occurrence frequency of food i

 

 = Total of Vi x Oi of all food types

 

IP = Index of Preponderance (%).

 

For selectivity estimations the [20] index was used:

 

 

Where Ei is the percentage by number of taxon i in the stomach contents, and Bi is the percentage by number of taxon i in the benthos. Positive values indicate that the fish selected the relevant prey.

The Gastrosomatic Index (GSI) was calculated to show the trends in the feeding activity of the fish according to [21] using the formula:

 

GSI = 100Wf/Wt

 

Whereas, Wf = Weight (g) of food in the gut; Wt = Total weight (g) of the fish

 

The Gut repletion index (GRI) was calculated according to [22] using the formula:

 

×100               

 

 

RESULTS

 

Food and feeding habits of dominant fish in Forcados river estuary

 

Clupeidae

 

A total of 1133 stomachs of E. fimbriata were analysed. Of these 1095 (96.73%) had food items while 38 (3.27%) had empty stomachs. Table 1 shows that the species fed predominantly on Microcystis and accounted for 24.99% (the highest percentage) of the food items by percent occurrence frequency while Macrobrachium sp had the highest by percent volume of food (42.3%). The least of 2.12% and 1.07% by percent occurrence frequency and percent volume of food were recorded for Desmids and Diatoms in Forcados river estuary. Callinectes sp recorded the highest Index of Preponderance (26.09%) followed by Macrobrachium sp (23.6%)., Microcystis (20.39%), Closterium (12.89%), Oscillatoria sp  (11.27%), Nitzshia (3.03 %), Rivularia (0.87 %), Desmids (0.74 %), Cosmarium (0.67 %) and the least was Diatoms (0.58).

 

Monthly variations in feeding habits of Ethmalosa fimbriata

 

Fig. 1 presents the monthly variations in the feeding habits of E. fimbriata. Algae and crustaceans were fed upon throughout the study period. The food items were fed upon regularly during both seasons. Peak consumption of algae was in the month of August, 2013 while crustacean had its peak in the month of October, 2012. The consumption of these food items did not follow any seasonal pattern.

 

Monthly variations in feeding Intensity of E. fimbriata

 

Variations in the number of empty stomach (Fig. 2) were used to study the variation in the feeding intensity of the species. There were no empty stomachs in May, 2012, October, 2012 and July, 2013. The lowest number of empty stomachs (2) was in the month of October, 2013, while the highest was in May, 2013. Again, the number of empty stomach was also generally higher in the rainy season months than the dry season.


 

 

Table 1: Summary of food items consumed by E. fimbriata in Forcados river estuary.

Food item

% Oi

%Vi

Vi x Oi

IP

Blue green algae

 

 

 

 

Oscillatoria sp

21.46

3.72

79.83

11.27

Microcystis

24.99

5.78

144.44

20.39

Total Blue green algae

46.45

9.5

 

 

 

Green filamentous algae

 

 

 

 

Closterium

21.04

4.34

91.31

12.89

Rivularia

3.48

1.78

6.19

0.87

Desmids

2.12

2.5

5.3

0.74

Cosmarium

3.61

1.31

4.73

0.67

Diatoms

3.83

1.07

4.09

0.58

Nitzshia

10.72

2

21.44

3.03

Total Green filamentous algae

44.8

13

 

 

 

Crustaceans

 

 

 

 

Callinectes sp

5.25

35.2

184.8

26.09

Macrobrachium sp

3.93

42.3

166.24

23.47

Total Crustaceans

9.18

77.5

 

 

Σ (Vi x Oi)

 

 

708.37

 

Keys► Vi = percent volume of food ,  = percent occurrence frequency of food I,  IP = Index of Preponderance (%).`

 

 

Description: C:\Users\user\AppData\Local\Temp\screen.jpg

 

Fig. 1: Monthly variation in the feeding habits of E.  fimbriata

 

 

Description: C:\Users\user\AppData\Local\Temp\screen.jpg

 

Fig. 2: Monthly variation in the empty stomach of E. fimbriata April 2012 – March, 2014

 

 

 

Selectivity

           

Table 3 shows diet selectivity indices for the benthic species taken by E. fimbriata. The Ivlev index indicated two macroinvetrebrate as being selected by the fish: Callinectes sp and Macrobrachium sp with Ivev values of 0.75 and -0.57 respectively.

 

 

Table 3: Selectivity of macroinvertebrate consumed by E. fimbriata in Forcados river estuary.

 

Stomach %

Macroinvertebrate %

Ivev Index

Crustaceans

 

 

 

Callinectes sp

5.25

0.76

0.75

Macrobrachium sp

3.93

14.25

-0.57

 

 

Feeding intensity

 

Table 4 shows GSI and GRI values recorded by E. fimbriata. E. fimbriata recorded high GRI and GSI value of 96.75% and 2.83% respectively.

 

 

Table 4: GSI and GRI values recorded by E. fimbriata in Forcados river estuary.

Fish species

Mean GSI(%)

GRI (%)

Food items

Functional Feeding group

Ethmalosa fimbriata

2.83

96.75

Phytoplanktons, zooplankton, crustacean

Omnivorous (filter feeder)

 

 

 


DISCUSSION

 

Of these 1095 (96.73%) had food items while 38 (3.27%) had empty stomachs indicating that this species were active feeders. The high GSI and GRI values recorded is also a confirmation of this finding. The species fed predominantly on Microcystis and accounted for 24.99% (the highest percentage) of the food items by percent occurrence frequency which is a reflection of its availability and abundance while Macrobrachium sp had the highest by percent volume of food (42.3%). This could be as a result of its relatively large size and also abundance.

 The food items varied from microscopic items such as planktons to macroscopic ones such as Crustacean implying that the fish took great advantage of the resources available in the water body. The success of mullets according to [23, 24] also lies in their feeding habits and the abundance of their food.

According to [25], seasonal changes in the dietary composition of a fish species are a reflection of the availability and abundance of each item. The consumption of food items recorded in this study did not follow any seasonal pattern. Hence, there were no fluctuations in the food items. The number of empty stomach was generally higher in the rainy season months than the dry season, implying that this species fed heavier in the dry season than in the rainy season. For food selectivity estimations the macroinvertebrate positively selected by E. fimbriata was Callinectes sp. indicating that the fish made the right choice of food since crabs are abundant in the water body.

 

 

CONCLUSION

 

The study indicated that E. fimbriata fed on phytoplankton as a major diet. Research on the food and feeding habits of economic fish species in an aquatic ecosystem should be continuous.

 

 

Author’s Contribution

 

E.O. conceived and designed the analysis, collected and analyzed the data and drafted the manuscript. A.J. and B.O.B. constructed aspects of the body of the manuscript and reviewed the article for spelling, grammar and intellectual content.

 

 

REFERENCES

 

[1] Oronsaye CG, Nakpodia FA. A comparative study of the food and feeding habits of Chrysichthys nigrodigitatus and Brycinus nurse in a tropical river. Pak J Sci Ind Res 2005; (48):118-121.

[2] Fagade SO, Olaniyan CIO. The biology of the West African shad, Ethmalosa fimbriata (Bowdich) in the Lagos lagoon, Nigeria. J Fish Biol 1972; (4):519-533.

 

[3]Marcus, C., 1984. Biology of bonga fish; Ethmalosa fimbriata (Bowdich): in the Nigeria Coastal and brackish waters project (NF) 1,2. Annual Report, Nigeria Institute for Oceanography and Marine Research Lagos. pp: 232.

[4] Ekeng, E.O., 1990. Length-weight and diet composition of Ethinalose fimbriata (Bowchch). Pliscea: clupeidae in Cross River estuary, Nigeria. B.Sc. Project University of Calabar. Cross River State, Nigeria, pp: 36.

[5] Ikomi, R. B. (1991). Observations on the bonga (Ethmalosa fimbriata (Bowdich, 1825) in Kulama Creek (Niger Delta, Nigeria). ACTA Hydrobiologia, 33(3/4): 335 – 344.

[6] George, U. U., Idung, J. U., Andem, A. B., Okorafor, K. A. and Mowang, D. (2013). Diet Composition and Condition Factor of Ethmalosa fimbriata in the Cross River   Estuary. Greener Journal of Biological Sciences, 3 (6):244-252.

[7] Abowei, J.F.N. (2009). The Morphology, Abundance, Condition Factor and Lengt weight Relationship of Ethmalosa fimbriata (Bowdish 1825) from Nkoro River Niger Delta, Nigeria. Advance Journal of Food Science and Technology, 1(1): 51-56, 2009 ISSN: 2042-4876© Maxwell Scientific Organization.

[8] Ekpo, I. E., Essien-Ibok, M. A. and Nkwo, J. N. (2014). Food and feeding habits and condition factor of fish species in Qua Iboe River estuary, Akwa Ibom State, southeastern Nigeria. International Journal of Fisheries and Aquatic Studies 2014; 2(2): 38-46

 [9] Idodo-Umeh, G. 2003. Freshwater fishes of Nigeria (taxonomy, ecological notes, diets and utilization). IdodoUmeh Publishers, Benin, Nigeria. ISBN-13: 9789788052012. 232pp.

[10] Opute, F. I. (2000). Contribution to the knowledge of algae of Nigeria. I. Desmids from the Warri/Forcados Estuaries. Part II. The elongate baculiform desmids. J. Limnol., 59(2): 131-155.

[11] Fischer, W., Bianchi, G. and Scott, W. B. (1981). FAO species identification sheets for fisheries purposes. Eastern Central Atlantqic: Fishing Areas 34 and Part of 47. Food and Agriculture Organization of the United Nations.

[12] Schneider, W. (1990). FAO Species Identification Sheets for Fishery Purposes. Field Guide to the Commercial Marine Resources of the Gulf of Guinea. FAO Regional Office for Africa,

[13] Paugy, D., Leveque, C. and Teugels, G. G. (2003). The Fresh and Brackish Water Fishes of  West Africa. Vol. II. IRD Editions, Publications Scientifiques du Museum, MRAC, 2003. p.815.

[14] Hynes, H. B. N. (1950). The food of freshwater sticklebacks (Gasterosteus aculeatus and Pygosteus pungitius) with a review of methods used in studies of the food of fishes. Journal of Animal Ecology, 19:26-28.

[15] Hyslop, E. J. (1980). Stomach content analysis: A review of methods and their application. Journal of Fish Biology, 122:71-80.

[16] Junior, S. E. L. and Goitein, R. (2001). A new method for the analysis of fish stomach contents. Journal Maringa, 23 (2): 421-424.

[17] Agbabiaka, L. A. (2012). Food and feeding habits of Tilapia zillii (Pisces: Cichlidae) in River Otamin South-Eastern Nigeria. Bioscience Discovery, 3 (2): 146-148.

[18] Oso, J. A., Ayodele, I. A. and Fagbuaro, O. (2006). Food and feeding habits of Oreochromis niloticus (L) and Saratherodon galilaeus (L) in Tropical Reservoir. World Journal of Zoology, 1 (2): 118-121.

[19] Nataragan, A. V. and Jhingram, A. G. (1961). Index of preponderance – A method of grading the food elements in the stomach analysis of fishes. Indian Journal of Fisheries, 8:54-59.

[20] Ivlev, V. S. (1961). Experimental ecology of the feeding of fishes. Yale University Press, New Haven, Connecticut, USA.

[21] Khan, M. S., Ambak, M. A. and Mohsin, A. K. M. (1988). Food and feeding biology of a tropical catfish, Mystus nemurus with reference to its functional morphology. Indian Journal of Fish, 29 (35):78-84. 29

[22] Ekpo, I. E., Essien-Ibok, M. A. and Nkwoji, J. N. (2014). Food and feeding habits and condition factor of fish species in Qua Iboe River estuary, Akwa Ibom State, southeastern Nigeria. International Journal of Fisheries and Aquatic Studies, 2(2): 38-46.

[23] Kurian, A. (1975). The Identification of Grey Mullet species by disc Electrophoresis. Aquaculture, 5:99-106.

[24] Payne, A. I. (1976). The relative abundance and feeding habits of the grey mullet species occurring in an Estuary in Sierra Leone, West Africa. Marine Biology, 35 (3): 277-286.

[25] Beumer, J.P. 1978. Feeding ecology of four fishes from a mangrove creek in North Queensland, Australia. J. Fish Biol., 12: 475-490.


 

 

Cite this Article: Ogidiaka, E; Atadiose, J; Bekederemo, BO (2019). Dietary Composition and Macroinvertebrates Selectivity of Ethmalosa fimbriata in Forcados River Estuary, Delta State, Nigeria. Greener Journal of Biological Sciences, 9(2): 59-64.