Population Estimation of Oncorhynchus mykiss, Salmo trutta and Schizothorax plagastimous in Upper River Swat, Khyber Pakhtunkhwa, Pakistan

Research Article

Ann Agric Crop Sci. 2021; 6(1): 1068.

Population Estimation of Oncorhynchus mykiss, Salmo trutta and Schizothorax plagastimous in Upper River Swat, Khyber Pakhtunkhwa, Pakistan

Khan T1, Hayat S2, Ullah F3*, Hayat H4, Ali S2, Khan S5 and Ahmad M1

1Department of Fisheries and Aquaculture, University of Veterinary & Animal Sciences, Pakistan

2Department of Livestock & Dairy Development, Khyber Pakhtunkhwa, Pakistan

3Lasbela University of Agriculture, Water and Marine Sciences, Pakistan

4Department of Pathology, University of Veterinary and Animal Sciences, Pakistan

5Department of Dairy Technology, University of Veterinary & Animal Sciences, Pakistan

*Corresponding author: Farman Ullah, Lasbela University of Agriculture, Water and Marine Sciences, Faculty of Veterinary and Animal Sciences, Uthal, Balochistan, Pakistan

Received: January 12, 2021; Accepted: February 03, 2021; Published: February 10, 2021

Abstract

This study was designed to assess the population status of Oncorhynchus mykiss (Rainbow trout), Salmo trutta (brown trout) and Schizothorax plagastimous (swati fish) in river Swat. Data were collected from four Sub- Areas (SAs) namely Madyan (SA1), Mankiyal (SA2), Kalam (SA3) and Mahoo Dhand (SA4). Fishes captured with electrofisher were identified morphologically and the wet weight and body length were determined. A total of 502 fishes were captured and identified. The highest capture (206) was recorded at SA4 whereas the lowest (64) at SA1. Similarly the highest captured specie (276) was Salmo trutta while the lowest (22) was Schizothorax plagastimous. The body length ranged from 15-36 centimeters whereas the wet weight varied from 47- 304 grams. Out of 502 fishes, 64, 104, 124 and 206 were from SA1, SA2, SA3 and SA4, respectively. The mean wet weight of Oncorhynchus mykiss, Salmo trutta and Schizothorax plagastimous 137.15g, 124.57g and 138.85g, respectively.

Keywords: Population estimation; Trout fish; Upper river swat; Electro fishing

Introduction

RIVER Swat starts from Mahoo Dhand at an elevation of about 3,000 meters, passes through the valley of Swat and flows for about 160 kilometer across the valley up to Chakdara. Total length of the river is 250 kilometers from Kalam to river Kabul near Charsadda. River Swat provides habitat for various fish species especially the trout in the upper part. The valley is mainly known for its abundant fish resources [1]. Trout belong to the group of fishes known as Salmonids. The typical coloration of rainbow trout is blue to olive green above the lateral line, a pink band along the lateral line and silver below the lateral line. Brown trout have generally some shade of brown on the back and side, fading to yellow on the belly, spots are large and black [2].

Materials and Methods

Permission from fishery department

Before starting the field work, permission was obtained from the Fishery Department, Khyber Pakhtunkhwa and a research officer of the Trout Culture & Training Center (TCTC) Madayn, Swat was deputed by the department for technical assistance & facilitating the work.

Site selection

The subareas selected for fish capturing were: Madyan, Mankiyal, Kalam, and Mahoo Dhand indicated as SA1, SA2, SA3, SA4, respectively.

Fish capturing

Fishes were captured through electrofisher, a common scientific survey method used to sample fish populations to determine abundance, density, and species composition [3-5]. Electrofishing caused no permanent harm to fish and fish usually returned to their natural state in as little as two minutes after being stunned. The captured fishes were identified on the basis of morphological characteristics.

Statistical analysis

The data were analysed by Analysis of Variance (ANOVA) through SAS 9.1 statistical software and Duncan’s Multiple Range Test (DMRT) was applied to compare means [6].

Results and Discussion

The studies were conducted at four Sub-Areas (SAs) of the upper river Swat viz: Madyan, Mankiyal, Kalam and Mahoo Dhand denoted by short words of SA1, SA2, SA3 and SA4, respectively. The details of captured fishes from each sub-area are given as under.

Subarea madyan (SA1)

From SA1, 64 fishes (56 S. plagastimous and 8 O. mykiss) were captured. Mean wet weight of S. plagastimous and O. mykiss was as recorded as 121.85±46.24 g and 130.25±45.02 g whereas mean body length of S. plagastimous and O. mykiss was as recorded as was recorded as 20.73±3.80 cm and 21.75±2.5 cm, respectively. The relative abundance of S. plagastimous and O. mykiss was 87.5 % and 12.65 %, respectively (Table 1).