Impact of abiotic factors on some biological indices of Cyprinus carpio (L., 1758) in Ghrib dam lake, (Algeria) Meriem Attal1,2* , Fouzia Attou1, Mounia Baha2 and Abdeslem Arab1 1
U.S.T.H.B.: Dynamic and Biodiversity Laboratory, Faculty of Biologic Sciences (FSB), BP32, El Alia 16000, Algiers, Algeria and 2Ecole Normale Superieure, BP. N°92, 16308, Vieux -Kouba, Algiers, Algeria
Abstract This study was conducted with a sample of 733 Cyprinus carpio collected between May 2013 and February 2016 from the ecosystem lake in the Ghrib dam which is eutrophic. Cyprinus carpio in this dam is characterized by a single fractional spawning that begins in the spring and ends in the late summer. The distributions of the viscerosomatic and gonadosomatic indices decrease between the spring and summer seasons. These periods correspond to the spawning period and the biological break of this species. They progressively increase between autumn and winter when the biological activity of the species returns. The hepatosomatic index progressively decreases between the spring and the summer when the hepatic reserves are used for reproduction. The repletion index shows that the trophic activity of C. carpio is intense in the spring. The condition factor varies between 1.1 and 1.35. The evolution of the biological indices of both sexes is well stressed in well-defined periods according to the seasons. The values are weak for males and high for females. The redundancy analysis allows the characterization of the influence of the physico-chemical parameters of the dam water, especially the role of the nutritious elements, in the biological seasonal cycle of C. carpio. Key words: Algeria, biological indices, Cyprinus carpio, dam, physico-chemical parameters, reproduction
Resume Cette etude a ete menee sur un echantillon de 733 Cyprinus carpio recoltes entre mai 2013 et fevrier 2016 dans l’ecosysteme du lac de barrage du Ghrib qui est eutrophique. Dans ce barrage, C. carpio se caracterise par un frai modere unique qui commence au printemps et se *Correspondence: E-mail:
[email protected]
la fin de l’ete. La distribution des indices viscerotermine a somatiques et gonado-somatiques diminue entre le prin la periode de temps et l’ete. Ces periodes correspondent a la pause biologique de cette espece. Ils augmentent frai et a progressivement entre l’automne et l’hiver, lorsque l’activite biologique de cette espece reprend. L’indice hepatosomatique diminue progressivement entre le printemps et l’ete, lorsque les reserves hepatiques sont utilisees pour la reproduction. L’indice de repletion montre que l’activite trophique de C. carpio est intense au printemps. Le facteur de condition varie de 1,1 a 1,35. L’evolution des indices biologiques des deux sexes est marquee par des periodes bien definies selon les saisons. Les valeurs sont faibles pour les m^ ales et elevees pour les femelles. L’analyse de redondance permet la caracterisation de l’influence des parametres physico-chimiques de l’eau du barrage, et specialement le r^ ole des elements nutritifs dans le cycle biologique saisonnier de C. carpio.
Introduction Cyprinus carpio is considered one of the eight fish species on the list of the International Union for the Nature Conservation (IUCN) of the worst 100 invaders (Lowe et al., 2000) and a major species in world aquaculture (FAO & da Silva, 2016). The wild ancestors of the common carp came from the Black Sea, the Caspian Sea, and the drainage of the Aral Seas, where it spread to the east to Siberia and China and the west as far as the Danube (Balon, 1995) and has since been introduced in many countries worldwide (Billard, 1995). In Algeria, C. carpio was introduced between 1860 and 1870 (Dieuzeide & Rolland, 1951) to the Mitidja rivers by the French colonization (Kara, 2011).
© 2017 The Authors. African Journal of Ecology Published by John Wiley & Sons Ltd 1 This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
2 Meriem Attal et al.
The repopulation and the introduction of fish species are management techniques widely spread in Algeria during these last years. These interventions often aim to improve the water quality by the introduction of C. carpio to diminish the risks of siltation and eutrophication of reservoirs, whilst improving inland fisheries (Attou & Arab, 2013). A lake ecosystem that benefited from this operation is the Ghrib Reservoir, which observed the first introduction of C. carpio in 1977. This fish species is a large, socioeconomical interest (Kara, 2011). It is an important source of food, especially for rural populations living far from the coast in Algeria (Mimeche, Belhamra & Mimeche, 2016). For the better management of this resource, it is necessary to understand its biology and its ecology in its biotope. The productivity and availability of C. carpio depend upon the parameters of the water quality, which play a great role in its growth, maturity, reproduction and development (Manon & Hossain, 2013). In our study, we present the results of a 3-years follow-up in a lake
ecosystem, the Ghrib Dam, located in north-central Algeria to (i) characterize its seasonal biological activity and (ii) identify the physico-chemical parameters of the dam waters affecting this activity.
Materials and methods Study area The Ghrib Reservoir is situated in the province of Ain Defla, west-central Algeria. It is built on the Chelif River at an average altitude of 460 m, with latitude 36°080 41.66N and longitude 02°340 18.08E. This strategic location makes it one of the most important dams in Algeria, extending over 1400 hectares, with a capacity of up to 280 millionm3 (Fig. 1). The general climate of this region is subhumid, with a temperate winter and a dry period from mid-May until the end of October.
Fig 1 Geographical location of Ghrib dam
© 2017 The Authors. African Journal of Ecology Published by John Wiley & Sons Ltd
Impact of abiotic factors
Fish and water sampling A passive fish sampling technique was used, and the capture was conducted over 24 h. The nets were 50 m in length and 1.5 m high, with gaps in the mesh between 18 mm and 75 mm. Fishes were sampled monthly between May 2013 and February 2016. The water was sampled vertically at the surface with an ordinary 1.5-l bottle.
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C. carpio, we used a redundancy analysis (RDA) (Borcard, Gillet & Legendre, 2011), which was completed by a Monte Carlo permutation test. This study was made possible with the help of language R (CRAN, 2016).
Results Physico-chemical parameters of the water
Study methods The physico-chemical properties of the water were recorded, including the temperature (T water in °C), dissolved oxygen (O2d in mgl1), pH, conductivity (Cond in lScm1) and salinity (Sal in &), which were measured with a multi-analyser (WTW 340i). Nitrates (NO3), nitrites (NO2), phosphates (PO4), calcium (Ca) and magnesium (Mg) were measured in the laboratory by colorimetric and titrimetric methods expressed in mgl1 (Rodier, 2005). For fishes, we measured the total length of the body (cm) with an ichthyometer (precision 0.1 cm) and determined the total body weight with an ordinary balance, with 1 gram precision. The viscera were weighed with a balance (precision of mg). We recorded the weight of the total viscera, the weight of the gonads, the weight of the liver and the weight of the full digestive tube. For the characterization of the nutritional and reproductive activities of C. carpio, the following biological indices were used: the viscerosomatic index (VSI), which is the ratio of the weight of the total viscera to the total body weight; the gonadosomatic index (GSI), which is the ratio of the weight of the gonads to the total body weight; the hepatosomatic index (HSI), which is the ratio of the liver weight to the total body weight; and the repletion index (RI), which indicates the stomach contents to the total body weight of the individual (Ighwela, Ahmad & Abol-Munafi, 2014; Jan & Ahmed, 2016). The condition factor is defined by Ricker (1987) as follows: K = (WL3) 100. For the statistical analysis, we used the Shapiro–Wilk normality test and the Mann–Whitney comparison test for the means (for two means, in the case of nonparametric data). The Kruskal–Wallis test (for many means, in the case of nonparametric data) and an ANOVA (for several means, in the case of parametric data) were used. The generalized additive model (GAM) was used to assess the variability of the physico-chemical parameters of the water. To show the influence of the physico-chemical parameters of the water on the biological indices of
The results of the physico-chemical analysis of the water are shown in Table 1. They show that the Ghrib dam is eutrophic. According to the Shapiro–Wilk normality test, the pH, nitrates (NO3), magnesium (Mg) and dissolved oxygen (O2d) correspond to a normal distribution (P-value >5%, Table 1). Nitrites (NO2), phosphates (PO4), calcium (Ca) and salinity (Sal) do not follow a normal distribution (P-value
