Amina Zuberi

Effects of cypermethrin on survival, morphological and biochemical aspects of rohu (Labeo rohita) during early development

The present study was conducted to investigate the effect of sub-lethal doses of Cypermethrin (CYP) on the survival and morphological and biochemical aspects of rohu (Labeo rohita) during early developmental stages. Newly fertilized eggs were incubated in the presence of sub-lethal concentration of CYP (20% of LC50 i.e., 8.43 μg L(-1)) in a well designed flow through system. Increased mortality was found with increase in exposure time. Deformities like eroded yolk and margins, elongated yolk sac, larvae with short tail, no eyes or larvae with zigzag movement and paralyzed larvae were observed in CYP treated group from blastula to fry stage. The activities of antioxidant like Catalase (CAT), Peroxidase (POD) and Lactoperoxidase (LPO) were decreased from 24 to 96 h in the control group whereas increased in CYP treated group. The Glutathione reducatse (GR) activity was also increased with time in both the control and treated groups; however, the activity was significantly higher in CYP treated group. Similarly, the whole body cortisol level showed an increasing trend with time in both control and treated groups. However, in CYP exposed group the cortisol level was considerably higher after 24 h exposure but statistically comparable to the control group after 96 h. It can be concluded from the present results that CYP even at very low concentration adversely affects the early development of L. rohita and enhances mortality. The obtained results reveal that CYP may affect the wild population of fish by inducing oxidative stress and modulating stress response during early ontogenesis.

Heavy metals in three commercially valuable cyprinids in the river Panjkora, district Lower Dir, Khyber Pakhtunkhwa, Pakistan

This study was conducted in river Panjkora (Khall, upstream; Timergara, downstream) and its tributary (Konhaye stream, reference site) at district Lower Dir. The study was aimed to assess heavy metal load in gills, liver, kidneys, and muscles of three fish species, namely Schizothorax esocinus, Racoma labiata, and Crossocheilus diplocheilus. The heavy metals, including nickel, cadmium, lead, copper, zinc, chromium, iron, and manganese were determined using an atomic absorption spect-rophotometer. Nickel and cadmium were not detected in any of the collected specimens at all sampling sites. Concentration of the detected metals varied significantly depending upon fish species and tissue type. Crossocheilus diplocheilus showed higher accumulated concentration of heavy metals while R. labiata contained the least. Schizothorax esocinus and R. labiata displayed significant differences in their concentrations of metals. The order of accumulation of heavy metals in different tissues was liver>kidneys>muscles>gills. Data demonstrated that heavy metal levels in the studied species were within permissible limits and thus, apparently suitable for human consumption. Currently, the river contains a sewage burden, and continued heavy pollution may ultimately lead to serious problems in the future.

Dietary administration of the commercially available probiotics enhanced the survival, growth, and innate immune responses in Mori ( Cirrhinus mrigala ) in a natural earthen polyculture system

ABSTRACT The use of probiotics is considered effective for survival, growth and enhanced immune response in aquaculture. In the current study, effects of commercially available probiotic (Magic Plus) was investigated on survival, growth and immune response of Mori (Cirrhinus mrigala) in a polyculture system. The experiment was conducted for 90 days on 1200 fingerlings in two groups i.e. control and probiotic supplemented groups each having 600 fingerlings. Control group was fed with 35% protein basal diet without any supplements and the other group was supplemented with commercially available probiotic at the rate of (1012 CFU kg−1 diet). After 90 days, probiotic supplemented group was characterized with significant increase (p < 0.05) in growth parameters like, total weight, total length, %weight gain, specific growth rate and survival growth rate. Immunological indices like, lysozyme activity, white blood cells, total plasma protein level and immunoglobulin (IgM) of supplemented group were also significantly (p < 0.05) enhanced. Moreover, digestive enzymes i.e. cellulase, protease and amylase were also found to be significantly (p < 0.05) hyper‐active in probiotic supplemented groups. Haematological parameters like, RBCs, Hb, Hct, MCH and MCHC were also significantly (p < 0.05) increased. Thus, the current study strongly suggests that a commercially available probiotic Magic plus may serve as a healthy and immunostimulating feed additive in C. mrigala culture.

PROXIMATE COMPOSITION OF FRESHWATER RAINBOW TROUT (Oncorhynchus mykiss) IN RELATION TO BODY SIZE AND CONDITION FACTOR FROM PAKISTAN

Rainbow trout, Oncorhynchus mykiss can be classified as the premier salmonid species. It is one of the most famous fish species in nature. At the same time, is also recognized and accepted as farmed fish species in many countries, because of its exceptional nutritive quality, rapid growth (Tekeliog, 2000) and exceptionally tolerant to environmental conditions (Simonovic, 2001). Worldwide production of rainbow trout was 537,000 tons in 2005 (FAO, 2007). Europe was the largest producer with 273,000, while Asia produces 97,000 tons (Vandeputte et al., 2008). O. mykiss is endemic to the Western region of North America. In 1973, Pakistan imported this species from Japan and introduced in its water bodies. Compared to other sources of protein, fish is an excellent source of proteins and essential nutrients for human diet (Arts et al., 2001; Fawole et al., 2007). In the developing countries, fish is considered as one of the best sources of protein (Louka et al., 2004). The nutritional value of the whole body is often used as an index of fish quality (Reinitz, 1983). The nutritional value of fish meat comprises the contents of moisture, dry matter, protein, lipids, vitamins and minerals, plus the caloric value of the fish (Evangelos et al., 1989; Steffens, 2006), while body composition and flesh quality are also essential characteristics of farmed fish species for human consumption. Body composition and flesh quality influence the consumer acceptance and human consumption (Kause et al., 2002). The measurement of some proximate profiles such as protein, lipids and moisture contents is often necessary to ensure that they meet the requirements of food regulations and commercial specifications (Waterman, 2000). Moreover, information concerning the chemical composition of freshwater fishes in general is valuable to nutritionists concerned with readily available sources of low-fat, highprotein foods such as most freshwater fishes (Mozaffarian et al., 2003; Foran et al., 2005), and to the food scientist who is interested in developing them into high-protein foods, while ensuring the finest quality flavor, color, odor, texture, and safety obtainable with maximum nutritive value (Mohamed et al., 2010). Body composition is also influenced by a great number of factors (Love, 1957; Weatherley and Gill, 1983a,b). It is observed that changes in the fish body composition are according to the size (Naeem and Ishtiaq, 2011), condition factor (Naeem and Salam, 2010; Naeem et al., 2011), and sex (Yousaf et al., 2011). Touhata et al. (1998) have shown that water temperature also affects the body composition of fish. While Suseno et al. (2010) have reported high protein and low fat content in fish due to increasing depth. Condition factor has been used as an index of growth and feeding intensity (Fagade, 1979). A change of weight at a particular length, or a change of length, without corresponding change of weight with alters ‘K’ (Weatherly and Gill, 1987). Therefore, the ‘K’ value for a given fish Pak. J. Agri. Sci., Vol. 53(2), 497-502; 2016 ISSN (Print) 0552-9034, ISSN (Online) 2076-0906 DOI: 10.21162/PAKJAS/16.2653 http://www.pakjas.com.pk

Length-weight and length-length relationships of freshwater wild catfish Mystus bleekeri from Nala Daik, Sialkot, Pakistan

Length-weight (LWR) and length-length relationships (LLR) were determined for a freshwater catfish Mystus bleekeri (Day, 1877) collected from Nala Daik, Sialkot, Pakistan. A total of 105 specimens (56 males; 49 females) were collected from February to March, 2010. Each specimen was weighed (g) and measured (cm). The total length of specimens studied ranged from 5.5 to 7.8 cm. Linear regression analysis was used, first to compute the degree of relationship between length and weight and then among total (TL), standard (SL) and fork lengths (FL). LWR exhibited a highly significant correlation (P < 0.001). The overall value of the exponent of LWR (b = 2.62) suggested negative allometric growth. Results for LLRs indicated that these are highly correlated (P < 0.001). Furthermore, the first reference for separate male, female and combined sex of length-weight and length-length relationships for Mystus bleekeri was provided. Key words : Mystus bleekeri , length-weight relationship, length-length relationship, predictive equations.

Some morphometric relationship traits of Labeo bata (Hamilton, 1822) from Head Panjnad, Pakistan

In the present research work, 127 Labeo bata having diverse body size ranging from 8.20 to 16.00 cm total length collected from Head Panjnad, Pakistan were used for the analysis of some morphometrics, that is, length-weight and length-length relationships. Condition factor and their relationships to investigate growth external morphometric characters, that is, total length (TL), standard length (SL), fork length (FL), head length (HL), head width (HW), body girth (BG), dorsal fin length (DFL), dorsal fin base (DFB), pectoral fin length (PtFL), pectoral fin base (PtFB), pelvic fin length (PvFL), anal fin length (AFL), caudal fin length (CFL) and caudal fin width (CFW) showed highly significant correlation with both cases, that is, increasing total length and body weight. A significant positive relationship was found between condition factor (K) and body weight, while no significant correlation was found in condition factor and total length. Key words : Morphometry, length-weight, length-length relationship, condition factor, Labeo bata.

An overview of the ongoing insights in selenium research and its role in fish nutrition and fish health

In the present review, the ongoing researches about selenium research in fish nutrition have been comprehensively discussed. Selenium research is getting popularity in fish nutrition as it is required for the normal growth and proper physiological and biochemical functions in fish. Its deficiency or surplus amounts create severe problems in fish. It is available as inorganic form, organic form, and nano form. In fish, most of the previous research is about the selenium requirements for fish by using only one selenium source mainly the inorganic one. Selenium shows maximum biological activity and bioavailability when it is supplied in proper form. However, to differentiate the more bioavailable and less toxic form of selenium, sufficient information is needed about the comparative bioavailability of different selenium forms in different fish species. In fish, important data about the new forms of selenoproteins is still scarce. Therefore, it is necessary to focus on the determination and elucidation of the new selenoproteins in fish through the utilization of recent approaches of molecular biology and proteomics. The adaptation of these new approaches will replace the old fashioned methodologies regarding the selenium research in fish nutrition. Moreover, the use of molecular biology and proteomics-based new approaches in combination with selenium research will help in optimizing the area of fish nutrition and will improve the feed intake, growth performance, and more importantly the flesh quality which has a promising importance in the consumer market.

Some morphometric relationships of hatchery reared male population of Oreochromis mossambicus from Pakistan

In this study, length-weight (LWR), length-length relationships (LLR) and condition factor (K) of male Oreochromis mossambicus from Nursery Unit Dera Ghazi Khan, Pakistan were examined. The range of the total length (TL) was determined to be 13.20 to 18.10 cm. This study shows that b-value in the LWR (W = aL b ) for male O. mossambicus had isometric growth with b = 2.93. Morphometric characters, that is, standard length (SL), head length (HL), head width (HW), pectoral fin length (PtFL), pelvic fin length (PvFL), anal fin base (AFB) and caudal fin length (CFL) indicated high significance (P < 0.001), while dorsal fin length (DFL) indicated least significance (P < 0.05) correlation with increasing size. The condition factor (K) for O. mossambicus ranged between 1.68 and 2.20 and remained constant for total length and body weight.