Condition factor and length-weight relationship of Bagrus bayad macropterus (Daget, 1954) from Agbura River, Niger Delta, Nigeria

The study was carried out to determine length-weight relationship and sex ratio of a freshwater fish Amblypharyngodon mola (Hamilton 1822) collected from Dekar haor of Sunamganj district during the period of January to August 2017. A total of 2000 fishes were collected for the study and categorized these fishes into three groups namely males, females and combined sexes. Among 2000 mola 777 were male and 1223 were female. Length-weight equations and the correlation coefficients obtained for males, females and combined ones were: males Y = –1.97 + 3.00X, r = 0.883; females Y = –2.30 + 3.41X, r = 0.914 and combined Y = –2.11 + 3.16X, r = 0.904. Female’s A. mola attained more weight with the increases in length. Value of correlation coefficient ‘r’ was 0.883 for male and exhibited highly positive correlation between length and weight. On the contrary, ‘r’ value for female was 0.914 and it had also strongly positive correlation between length and weight relationships. Length-weight relationship of A. mola for male, female and combined sexes showed allometric pattern of growth. Condition factor ‘K’ for male, female and combined sexes was 1.09, 1.05 and 1.06, respectively and indicated better condition of fishes. The highest sex ratio (1 : 2.05) was found in May and the lowest (1 : 1.33) was in February. Dominance of females over males throughout the year was observed with an average ratio of male and female 1 : 1.57. Therefore, results of the study indicate that the existing hydrobiological conditions of the haor are conducive for food availability, free movement, feeding and better growth of the fish. Asiat. Soc. Bangladesh, Sci. 44(2): 185-193, December 2018

The present work reports the length–weight relationships (LWR) and condition factor and of Cirrhinus cirrhosus inhabiting in River Indus, Sindh-Pakistan. The Length-weight relationship is an important tool for fishery management. A total of 340 specimens (individual) of length–weight were measured. A maximum length of the groups was observed 20.7cm and minimum as 9.4cm. The maximum weight was recorded about 84gm and minimum as 6gm. The estimated values of length-weight relationship and condition factor were calculated by formula LeCren (1951), as Kn=0.547, and Fulton as K=0.724. Length-weight was found with a strong correlation of n= 3.101, C=0.0176 with r2=0.894. The results of this work would be beneficial for sustainable management as well as fishery managers.

Bilih (Mystacoleucus padangensis) is an endemic species of Lake Singkarak and has important economic value. Overfishing of Bilih fish using non-selective fishing gear has led to a decline in its population. High demand, resulting in decreased production and size of Bilih fish. This research aims to determine this endemic fish's length-weight relationship and condition factor as basic data to the effort conservation. The fish was captured with experimental gillnet mesh sized 5/8, ¾, and 1 inch in Sumani, Batu Taba, Paninggahan, and PLTA intake stations. The total length and the weight of Bilih fish ranged from 40 – 95 mm and 10 – 74 mg, respectively. The highest length and weight of Bilih were 80.3 mm, and 45.0 mg were found at the Sumani station. The growth pattern of male and female fish was a negative allometric characteristic. The length-weight relationship of male and female fish was W = 0.00137 L2.368 and W = 0.00179 L2.312, respectively. Condition factors of males and females are 1.02 and 1.004, respectively. The result of condition factor value for males is higher than the female. The water quality values are within the normal range that supports fish life.

Twenty specimens of triploid with weight and length ranging from 207-300g and 29-32cm; diploid 150-200g and 23-28cm Heterobranchus bidorsalis (Geoffroy St. Hilaire 1809) were subjected to morphometric and meristic characterization, length-weight relationship and condition factor evaluation. Triploid specimens had the higher values in all the parameters examined and were significantly different (P<0.005). Regression analysis of diploid and triploid show the ranges of values (K) of 0.802 1.453 and 0.838 0.906 respectively, for condition factor (k) while the relative condition factor values (Kn) ranged between 0.869 1.087 and 0.968 1.038 respectively. Weight increases directly as the total length increases for both diploid and triploid indicating isometric growth. The R2 in triploid was higher (96.8%) than in diploids (42.4%). In diploid progenies, the length by weight was significantly different (P<0.05) in triploid. Triploid progenies need no special adaptive environment or technique for rearing. Therefore, diploid and triploid progenies can be successfully cultured simultaneously under the same environmental condition.

The existence of gold mining activities in mailil river can disrupt the stability of the ecosystem, fishing by using toxins, which may result in a decrease in fish populations in the river mailil. This study aims to obtain information related to biological and ecological aspects (Barbonymus gonionotus) in river Mailil, Village. This study was conducted from November 2020 to January 2021. The locations for sampling were determined based on information from the local community in Bandar Kumbul Village. Samples were caught using nets, traps, and nets Sampling was conducted from 09:00 am to 03:00 pm. The biological aspect being measured was the length-weight relationship of the fish using the linear allometric model (LAM). Meanwhile, the ecological aspect being measured was the condition factor using Fulton’s K equation and relative weight (Wr) equation. In this study, 54 silver barbs (B. gonionotus) were successfully caught as samples. The results of the length-weight relationship analysis indicated a negative allometric relationship with the value of b = 0.52 (b < 3). Furthermore, the value of Fulton’s K condition factor was 27.75, while the value of relative weight (Wr) condition factor was 100.07. These results indicated that river Mailil as an ecosystem and habitat of silver barbs is in the balance condition.Keywords: Length-weight relationship, Barbonymus gonionotus, aek mailil

The length-weight relationship of a newly described catfish Pangasius silasi Dwivedi et. al., 2017 was studied from 88 specimens collected from the native distribution range of the species i.e. Nagarjuna Sagar Dam, Telengana, India. The total length and weight of the sampled fishes ranged from 290 to -590 mm and 240 to 2300 g respectively. Results of regression analysis showed that the regression coefficient (r²) values varied from 0.985 to 0.989. The average condition factor observed was 1.04 and 0.98 for males and females respectively. Positive allometric growth and condition factor of the species indicated the potential of the species for aquaculture. The information generated will also be useful in sustainable management and conservation of the species in natural waters.