Positive Allometric Growth Pattern Research Articles

Biometry, condition factors and length-weight relationships of sixteen fish species in Iwopin fresh-water ecotype of Lekki Lagoon, Ogun State, Southwest Nigeria

Study on biometry, length-weight relationships and condition factors of 139 fishes covering 11 families and 16 species inhabiting Iwopin fresh water ecotype of Lekki Lagoon, were provided. The fish species were obtained from the major landing sites of Iwopin from July to September, 2017. As a result, Chrysichthys nigrodigitatus was the most abundant while Polypterus senegalus, Sphyraena barracuda and Dagetichthys lakdoensis constituted the least groups of populations. The Fulton condition factor (K) values significantly (P < 0.001) ranged between 0.80 and 1.28 while b values varied from 1.067 to 3.41. The values of b indicated negative and positive allometric growth patterns. The highest mean total length value (33.2 ± 1.55) cm was found in Papyrocranus afer while the least mean total length value (7.9 ± 0.60) cm was found in Sarotherodon galilaeus. S. barracuda had the highest mean weight value (187.0 ± 72.9) g while S. galilaeus had the least mean weight value.

The Diversity of Fish Species, Composition and Abundance from Bodna River in Kwali Area Council, Abuja.

The Diversity of fish species, composition and abundance from Bodna River in Kwali Area Council, Abuja was studied between May 2018 to April 2019.The aim of the study was to determine the management and sustainable use of the fisheries resources of the Area council. About 1331 fish were collected from the artisanal fishermen during the study period and morphometric indices were determined using standard methods. The fish were identified and counted. Sex ratio 1:2:1 (Males to Females) was obtained indicating a male dominated population. Length –weight measurement indicated that the fish exhibited positive allometric growth pattern. The highest percentage abundant species in the site were Oreochromis niloticus with 34.8% Clarias garienpinus with 28.0% and Pellonula leonensis with 17.6% and the least occurring species were Nannocharax shariensis with 11.0% Mormyrus valenciensis with 7.7%. The seasonal variation of fish distribution was observed to be higher in the wet season with 66.2% than the dry season. Nutrient displayed greater impact on fish abundance in the wet season. The Simpson and Shannon Weiner’s diversity index values were (0.976) and (-1.456) in both richness and evenness respectively. The findings of the study could be helpful to the artisanal fishermen and the community for fisheries sustainability.

The Diversity of Fish Species, Composition and Abundance from Bodna River in Kwali Area Council, Abuja.

The Diversity of fish species, composition and abundance from Bodna River in Kwali Area Council, Abuja was studied between May 2018 to April 2019.The aim of the study was to determine the management and sustainable use of the fisheries resources of the Area council. About 1331 fish were collected from the artisanal fishermen during the study period and morphometric indices were determined using standard methods. The fish were identified and counted. Sex ratio 1:2:1 (Males to Females) was obtained indicating a male dominated population. Length –weight measurement indicated that the fish exhibited positive allometric growth pattern. The highest percentage abundant species in the site were Oreochromis niloticus with 34.8% Clarias garienpinus with 28.0% and Pellonula leonensis with 17.6% and the least occurring species were Nannocharax shariensis with 11.0% Mormyrus valenciensis with 7.7%. The seasonal variation of fish distribution was observed to be higher in the wet season with 66.2% than the dry season. Nutrient displayed greater impact on fish abundance in the wet season. The Simpson and Shannon Weiner’s diversity index values were (0.976) and (-1.456) in both richness and evenness respectively. The findings of the study could be helpful to the artisanal fishermen and the community for fisheries sustainability.

Analysis of the Biological Features of the Blue Tilapia, &lt;i&gt;Oreochromis aureus&lt;/i&gt; in the Garmat Ali River, Basrah, Iraq

The blue tilapia, Oreochromis aureus (Steindachner, 1864) is exotic fish and became widely distributed throughout different natural waters of Iraq during the last years. The present study describes the length compositions, age, growth, reproduction and food habit of the species in the Garmat Ali River from September 2018 to August 2019. A total of 1050 specimens were caught using gill nets, cast net, and electro-fishing. The lengths of O. aureus ranged from 6.6 to 22.9 cm, and the most dominant lengths were 14.0 to 18.0 cm representing 61.6% of the catch. A positive allometric growth pattern was observed for males (b= 3.317), females (b= 3.231) and all individuals (b= 3.283). There were three peaks for relative condition factor (Kn) that appeared during October, April, and July for both sexes. The age estimated on the basis of scales showed that the population comprised of 1 to 5 years. The parameters of the von Bertalanffy growth curve were L∞= 27.6 cm, K= 0.193 and to= 1.18. The growth performance index (ø) of O. aureus was computed as 2.17. The overall sex ratio (male: female) was1:1.04. Females attained sexual maturity at a lower size than males with mean size at first maturity determined as 6.6 cm for females and 9.2 cm for males. Two peaks of the gonado-somatic index were shown, the higher one in April and the lower one in September in both sexes. The estimated fecundity ranged from 352 to 1033 eggs in the fish ranging from 12.2 to 20.5 cm in length. O. aureus is an opportunistic feeder that will successfully utilize whatever food source is available, its diet comprised of detritus (43.1%), diatoms (23.9%), algae (22.8%), macrophytes (7.1%) and crustaceans (6.0%). The results highlighted basic biological features on invasion fish species which can assist in fisheries management and conservation of the fish species in Iraqi waters.

The biology of Goldsilk Sea Bream (family: Sparidae) from the inshore waters of north coast Kenya

The biology of the sparid, Acanthopagrus berda (goldsilk sea bream) was investigated using catch samples obtained from artisanal fishers at selected fish landing sites in the Marereni and Ngomeni fishing areas on the north coast of Kenya. This species has not previously been studied in Kenya although it forms significant proportions of artisanal fish landings and is also a promising aquaculture species. In order to contribute to knowledge of this species, the length-weight relationship, condition factor and feeding preference for prey items were studied in a total of 751 specimens sampled from July 2013 to July 2014. Length-weight relationships for male and female individuals from both fishing areas were strongly correlated (Males: Marereni - R2 = 0.920, Ngomeni - R2 = 0.983; Females: Marereni - R2 = 0.966, Ngomeni - R2 = 0.941). The condition factor of mixed sexes was not significantly different between the two fishing areas (Marereni 2.15 ± 0.08; Ngomeni 2.05 ± 0.02) at p &gt; 0.05. Gut content analysis recorded a total of 5 taxa in the diet (gastropods, molluscs, detritus, crustaceans and fish). The overall sample was dominated by female individuals with an overall sex ratio of females (405 individuals) to males (338 individuals) of 1:0.8 being significantly different at p &lt; 0.05. The species exhibited isometric and positive allometric growth patterns, indicative of the physiological well-being of this species on the north coast of Kenya. Gonadal maturation occurred throughout the year with peaks in July, August and September. However, more work is needed on the biology, distribution, spawning grounds, behavior, and migration patterns along the Kenyan coast.

Biological Aspect of Bullet Tuna Auxis rochei (Risso, 1810) in the Makassar Strait, West Sulawesi, Indonesia

Abstract The objectives of the present study were to determine the size distribution, growth pattern, feeding habit and stomach fullness index of bullet tuna Auxis rochei in the Makassar Strait, West Sulawesi. The research was conducted for six months between March and August 2017. Sampling collection was carried out using the handline technique. A total of 2160 fish were caught. Their total length ranged from 15.8 to 28.5 cm and weight ranged from 52.3 to 366.5 g. The total length of male fish ranged from 18.5 to 28.5 cm and weight ranged from 77.5 to 366.5 g. The total length of female fish ranged from 15.8 to 27.5 cm and weight ranged from 52.3 to 328.8 g. The growth pattern of bullet tuna for both male and female fish was classified into a positive allometry (b&gt;3); the type of food found in the fish gut consisted of crustacean (12.50% to 25.64%), chepalopods (7.32 to 34.80%) and unidentified (47.69 to 64.51%), respectively. Nonetheless, the predominant food condition was not identified and in the gut there was generally no food present. The stomach fullness index ranged from 1.13% to 7.18%, ¾ (12.11 to 15.74%), ½ (12.27 to 23.14%) and empty (59.26 to 65.74%). The length size distribution of male bullet tuna was larger than the female with a positive allometric growth pattern. However, the growth pattern of male and female bullet tuna statistically showed no difference.

Changes in some biological parameters of the silver cyprinid, Rastrineobola argentea (Pellegrin, 1904) in the Nyanza Gulf of Lake Victoria, Kenya

AbstractThe study examined length–weight relationship, condition factor, size at 50% maturity and fecundity of Rastrineobola argentea in the Nyanza Gulf of Lake Victoria, Kenya. The 500 fish examined had a mean length of 39.4 ± 0.3 mm SL, ranging from 17 to 55 mm SL and weighed between 0.08 and 2.44 g. The length–frequency analysis indicated a unimodal distribution between 35 and 40 mm SL, with a modal length at 37 mm SL. The fish exhibited a positive allometric growth pattern (b = 3.4). The condition factor for all fish was 1.02. Male fish showed a decreasing trend in condition factor with increasing body length, while females exhibited an increasing trend. The length at 50% maturity was estimated at 43 and 44 mm SL for males and females, respectively. The smallest mature male was 41 mm SL and 42 mm SL for females, with 100% maturity already exhibited at 49 mm SL. Fecundity varied from 235 eggs for 33 mm SL to 2,309 eggs for 54 mm SL fish. positive linear relationships were found between fecundity against standard length and ovary weight. Comparisons with previous studies in this lake over time indicated a decrease in length at maturity and an increase in fecundity, which are strategies to maximize reproductive success. The findings of this study provide useful information for managing the fishery.

Fish Assemblages, Growth Pattern and Environmental Factors in Upper Baleh River, Kapit, Sarawak

A survey of the freshwater fish composition in the upper Baleh River, Sarawak was conducted in 2015. A total of 1,538 specimens, comprising 45 species from nine families were collected using electrofishing devices and cast nets. The family Cyprinidae was the most dominant (62.9%) as well as diverse (42.2%) family, followed by the Balitoridae (31.0%; 31.1%) in the river. The three most dominant species were Tor tambra (18.1%), Lobocheilos ovalis (12.9%), and Parhomaloptera microstoma (11.3%). Shannon’s diversity index, Margalef’s richness index, and Pielou’s evenness index were 2.9, 6.0, and 0.8, respectively, an indication of moderate species diversity. Canonical Correspondence Analysis demonstrate that elevation, stream order and sedimentation were the most significant factors related to fish assemblages in the river, particularly for members of the families Cyprinidae and Balitoridae. The coefficient ‘n’ value in length-weight relationship for T. tambra, L. ovalis, and P. microstoma were determined as 2.92, 2.72, and 3.15, respectively. T. tambra and L. ovalis exhibited a negative allometric growth pattern which could be due to food competition whereas P. microstoma exhibited a positive allometric growth pattern as mountainous forest stream habitat offers favourable environmental conditions. The Fulton’s condition factor of each species indicates that T. tambra and L. ovalis were in poor condition, whereas P. microstoma was in extremely poor condition. It is hypothesized that environmental degradation caused by logging activities have affected the health of the most dominant fish species in the upper Baleh River. Further study should be conducted to determine the underlying factors that are affecting the fish diversity.

Length-Weight Relationship, Growth Patterns and Sex Ratio of Dog Conch &lt;i&gt;Strombus Canarium&lt;/i&gt; Linnaeus, 1758 in the Waters of Kota Batam

This study aims to analyze the aspect length of weight relationship, growth pattern, and sex ratio of Dog conch. This research was conducted in May-August 2018. The samples were collected from three locations (stations) which became the main of catching the Dog conch in Kota Batam, namely, Jaloh Island, Kangkung Bay, and Terong Island. A total of 377 individuals (162 males and 215 females) S. canarium were collected from three research stations. The value of the length-weight relationship for females, males, dan blended, at the respective station, are Jaloh Island, W=0,000142L 2,924 , R²= 0.555 (female), W=0,00049L 2,610 , R²= 0.566 (male), and W=0,000165L 2,881 , with a value of R²= 0.572 (blanded); Kangkung Bay, W=0,0850L 1,275 , R²= 0.325 (female), 0,00000511L 3,185 , R²= 0.776 (male), and W=0,0384L 1,480 , with R² = 0.374 (blended); As well as Terong Island, W=1,227L 0,746 , R²= 0.180 (female), W=0,00139L 2,385 , R²= 0.714 (male) and W=0,118L 1,305 with R²= 0.355 (blended). The pattern of growth of Dog conch is negative allometric (b 3) has a positive allometric growth pattern, where weight gain is faster than long increments. The sex ratio of Dog conch on Jaloh Island and Terong Island is balanced, while in Kangkung Bay it is not balanced. Overall the sex ratio in the study location is not balanced with a ratio of 1: 1.33 with the expectation frequency (Ei) of 188.8.

Some biological characteristics of Carassius gibelio (Bloch, 1782) (Teleostei: Cyprinidae) in the Azad dam Lake in Western Iran

The freshwater Prussian carp, Carassius gibelio (Bloch, 1782) is a cyprinid, known as a hazardous species for native fish communities. In the present study, some population parameters, including length-weight relationship ( LWR ), condition factor ( KF ), relation condition factor ( K n ), age and growth of C. gibelio in the Azad dam, Kordestan Province, Iran were estimated. The LWR indicating a positive allometric growth pattern. The von Bertalanffy growth parameters were estimated as L ∞ =337mm, K =0.255 yr -1 , t 0 =-0.21 yr. There was a significantly positive correlation between TL and KF ( r 2 =0.89). The average of K n was lower than 1 which suggested that the well-being of the fish was not good in the Azad dam region.

Growth of the Anchovy Anchoa tricolor in a brazilian subtropical estuary.

This study aimed to describe the growth parameters of Anchoa tricolor in a subtropical estuary. From August 2010 to July 2011, 10.009 specimens of the anchovy Anchoa tricolor, mean total length 4.2 cm (±1.45), were captured in the intertidal region of the Estuarine Complex of Paranaguá (25º 15' - 25° 35' S and 48° 20' - 48° 45' W). Species´s weight/length relationship for grouped genders was described as follow: W = 0.0000591.Lt3.282 (length in centimeters; weight in grams) showing a positive allometric growth pattern (b>3; P=0.000). Significant differences concerning weight/length relationship for males, females and unsexed individuals were identified. Parameters of the length to age growth curve were estimated by adjusting a von Bertalanffy growth equation from aged individuals from a length-frequency distribution: L∞ = 10.06 (1-e-17715(t + 0.205)) (length in centimeters, age in years). The age to attain 95% of the asymptotic length ( A95 ; longevity sensu Taylor) was estimated at 1.7 years. Size frequency distributions indicate that A. tricolor uses the estuarine area as reproductive and growing grounds, especially during the first year of the life cycle, where the species represent a key element for ecosystem functioning due to relatively high abundance and energy transference from plankton to top predators.

Length Weight Relationship and Condition Factor of Cultured Rainbow Trout, Oncorhynchus mykiss (Walabum, 1792)

A Length Weight Relationship (LWR) and condition factor of cultured rainbow trout Oncorhynchus mykiss was studied. A total of 144 specimens were used obtained from National fish farm Laribal, Dachigam during January 2017 to December 2018. The coefficient ‘b' value of LWR showed negative allometric (b&lt;3) growth throughout the year except in the months of October and December, where the positive allometric growth pattern was reported (b&gt;3). In order to generate more precise information, a trend line graph was draw to compare condition of fish in different months, which indicated declining growth pattern condition. The condition factor showed an overt variation with highest value was reported during the breeding season. The result obtained in this study will be useful for the improvement of production and quality of trout under cultured condition.

Condition factor and length-weight relationship of &lt;i&gt;Bagrus bayad macropterus&lt;/i&gt; (Daget, 1954) from Agbura River, Niger Delta, Nigeria

The study on length-weight relationship and condition factor of Bagrus bayad macropterus from Agbura River, a tributary of the Nun River was conducted monthly for eighteen months (April 2012 – December 2013). Three thousand, six hundred and forty (3640) fish samples comprising of one hundred and ninety-three (193) Bagrus bayad macropterus were collected using traditional fishing gear and drag nets. The specimens were preserved in ice-packed box and taken to laboratory for length-weight measurement. The length-weight relationship was estimated using the linear regression model 𝑊=𝑎𝐿𝑏 and condition factor (k) determined using the equation 𝐾=100𝑊𝐿𝑏 .The standard length ranged between 17.6 and 27.2 cm and the weight ranged between 170.56 and 501.30 g in males and 16.8 to 32.2 cm and 190.60 to 510.35 g in females. The value of length exponent was more than 3 showing positive allometric growth pattern. The b-values tested using ANOVA indicated a highly significant regression of weight on standard length (P<0.05). The correlation (r) between increase in length and gain in weight was significant. The condition factor ranged between 1.51 and 3.13 with mean k-value of 2.23. The k-values showed monthly variations with peak values between the months of January and April. The fish species was in good condition in the study area as the K values were above one throughout the period of study.Keywords: Condition factor, length- weight relationship, Bagrus bayad macropterus, Agbura River Niger Delta

Age and growth of brond-snout, Chondrostoma regium in Beheshtabad River of Chaharmahal & Bakhtiari Province of Iran (Teleostei: Cyprinidae)

The age and growth parameters of the brond-snout, Chondrostoma regium in Beheshtabad River of Chaharmahal & Bakhtiari Province were investigated during April 2013 to April 2014. The males ranged between 8.04-22.10cm and 5.20-105.00g. The females ranged between 7.84-23.15cm and 8.70-155.00g. Males were categorized in age classes 1 + -5 + and females in age classes 1 + -6 + . The age class 3 + was the dominant one in the whole samples. The length-weight relationship for males, females and all individuals was as W=0.0089L 3.045 (r 2 =0.95), W=0.0082L 3.109 (r 2 =0.85) and W=0.0107L 3.000 (r 2 =0.92), respectively, indicating a positive allometric growth pattern for the females and an isometric growth for the males and all fish. The age-length and age-weight relationships in males and females were estimated as L t =26.23[1-e -0.267(t+0.483) ], W t =160.77[1-e -0.267(t+0.483) ] 3.045 and L t =31.89[1-e -0.148(t+2.067) ], W t =266.11[1-e -0.148(t+2.067) ] 3.109 , respectively. The growth performance index (Ф') value was 3.84 in males and 2.18 in females, indicating a faster growth rate in males. The mean condition factor was 1.02±0.01 for males and 1.14±0.02 for females. The relative length of gut was 1.18±0.05 for all fish, indicating a herbivorous habit for this fish. The highest mean feeding intensity of males was in July and the lowest in March and April. In the female, the highest was in January and the lowest in June. The highest mean value of Gut vacuity index of males and females was in the spring and the lowest in summer. About 55% of the studied stomachs were full. The highest number of empty stomachs was in May (80%) and the lowest in July (32%). Based on the mean Gut vacuity index (48%), this fish is considered a medium feeding fish (40<VI<60).

Some Biological Parameters of the Three Commercially Important Fishes in Ethiopian Water Bodies: A Review

The findings on length-weight relationship and condition factor of the native Varicorhinus beso , endemic Labeobarbus nedgia and the African catfish Clarias gariepinus showed varied pattern in different water bodies of Ethiopia. Labeobarbus nedgia and Clarias gariepinus showed isometric growth pattern in most water bodies of Ethiopia. The African scarping feeder V. beso had positive allometric growth pattern in some of Ethiopian Rivers (Dura and Ardi). But, isometric growth pattern was recorded in Beshilo River for the same fish species. Varicorhinus beso and L. nedgia had better body condition than C. gariepinus in all water bodies. Generally, the length-weight relationship and condition factor of fishes is correlated with availability of food, feeding rate, gonad development, spawning period, water quality parameters can determine the growth rate and the condition of fishes and therefore, further study is required regarding on the variations of length weight relationship and condition factor are they controlled by genes or human induced environmental factors for sustainable fishery activities in aquaculture or wild fishing.

Allometric Growth Pattern and Morphological Changes of Pterophyllum Scalare (Schultze, 1823) During the Early Development

The early development of the angelfish (Pterophyllum scalare) was studied from 1 up to 51 days post-hatching under culture conditions. The left side of specimens was photographed and morphometric parameters, including total length, head length, tail length, trunk length, eye diameter, caudal peduncle and body depth, were measured using the software ImageJ. Allometric growth pattern was calculated as a power function of total length and the patterns in allometry were described by the growth coefficient to reveal important steps in the species’ early life history. In addition, the anatomical changes were described. The early development of this species was divided into four stages: the eleuthero-embryo, propterygio-larval, pterygio-larval and juvenile. During the first two stages, the growth rate of the head and tail was higher, whereas, in last two stages, the growth rate of the head decreased and the growth rate of the trunk increased, especially at the juvenile stage. This body shape changes revealed priorities to develop the organs related to vital functions such as branchial respiration, nervous system and exogenous feeding during preflexion stages (TL = 4.52–5.54 mm). The growth pattern of the trunk turned to relatively positive allometric growth pattern during the juvenile stages reflected in a deeper body shape along with developed long dorsal and anal fins and higher position of the pectoral fins, an adaptation to its adult lifestyle. The results confirmed this fact that morphological development and growth patterns during early life stages in P. scalare closely match its immediate required function.

Age and growth of Alburnus mossulensis (Cyprinidae) in Bibi-Sayyedan River of Isfahan Province

Population structure and growth of Mossul bleak, Alburnus mossulensis, a native species of cyprinids in Bibi-Sayyedan River of Semirom, Isfahan, were investigated by monthly sampling during December 2010 to December 2011. For this purpose, 543 speciments (353 females, 159 males and 31 immature) were caught using seine net (5 mm mesh size) and a cast net. Age groups of males and females were 0+ to 5+. The most frequent age group was 2+ in both sexes. The sex ratio was 1M:2.2F (p >0.05). The largest female was 16.80 cm in total length and 49.12 g in weight, while the largest male was 14.10 cm in total length and 28.19 g in body weight. The length-weight relationship was calculated as W = 0.0169L3.0355 (r2=0.95) for males, W=0.0061L 3.1751 (r2=0.98) for females and W=0.0066L3.139 (r2=0.99) for all fish (males, females and immature). Regression coefficient (b) based on Pauly test, was significantly different from 3 in females, but not in males (p <0.05), indicating an isometric growth pattern in males and a positive allometric growth pattern in females and all fish.

REPRODUCTION BIOLOGY EASTERN LITTLE TUNA Euthynnus affinis IN THE SUNDA STRAIT

&lt;em&gt;Eastern little tuna&lt;/em&gt; &lt;em&gt;is small pelagic fish that has high economic value. Fishing effort of the eastern little tuna for the last eight years have also exceeded the optimum level. To ensure the sustainability of the pelagic fish resources, it is necessary to perform the management efforts. This study was to observe reproductive Biology of the eastern little tuna, as one of the necessary information in the management of fishery resources. Fish -samples were collected from the catch of local fishermen in April-August 2015. Based on T test (α = 0,05), the eastern little tuna&lt;/em&gt; &lt;em&gt;males and females showed positive allometric growth patterns. Average size of the first time caught fish for the female (308,37 mm) and male (280,63 mm) was smaller than that observed in those first time maturity gonads (ranging 407-408 mm for female and 438-440 mm for male&lt;/em&gt;)&lt;em&gt;. &lt;/em&gt; &lt;em&gt;The eastern little tuna&lt;/em&gt; &lt;em&gt;spawn gradually or partially (partial spawner), and&lt;/em&gt; &lt;em&gt;have high reproductive potential with fecundity ranged 17.814-560.792 eggs (average fecundity: 109.807) in fish of 285-630 mm body length. The gonad maturity level of the eastern Little Tuna is dominated by Gonad maturity level I and II,(immature). The value of gonad maturity for the female level is about 0,0769-0,6879 and the male is 0,1913-0,3000.&lt;/em&gt;

REPRODUCTION BIOLOGY EASTERN LITTLE TUNA Euthynnus affinis IN THE SUNDA STRAIT

Eastern little tuna is small pelagic fish that has high economic value. Fishing effort of the eastern little tuna for the last eight years have also exceeded the optimum level. To ensure the sustainability of the pelagic fish resources, it is necessary to perform the management efforts. This study was to observe reproductive Biology of the eastern little tuna, as one of the necessary information in the management of fishery resources. Fish -samples were collected from the catch of local fishermen in April-August 2015. Based on T test (α = 0,05), the eastern little tuna males and females showed positive allometric growth patterns. Average size of the first time caught fish for the female (308,37 mm) and male (280,63 mm) was smaller than that observed in those first time maturity gonads (ranging 407-408 mm for female and 438-440 mm for male). The eastern little tuna spawn gradually or partially (partial spawner), and have high reproductive potential with fecundity ranged 17.814-560.792 eggs (average fecundity: 109.807) in fish of 285-630 mm body length. The gonad maturity level of the eastern Little Tuna is dominated by Gonad maturity level I and II,(immature). The value of gonad maturity for the female level is about 0,0769-0,6879 and the male is 0,1913-0,3000.

Length-weight relationships and condition factors of Alburnus zagrosensis Coad, 2009, from three rivers of Tigris basin in Iran (Teleostei: Cyprinidae)

The length–weight relationships and condition factors of 145 specimens for three populations of Alburnus zagrosensis Coad, 2009, an endemic species in Tigris River basin in Chaharmahal and Bakhtiari Province, Iran, were studied for the first time. The b value for Cheshmeh-Ali population was 3.19, for Hamzeh-Ali was 3.69 and for Polmari was 2.87, indicating a positive allometric growth pattern for Hamzeh-Ali and isometric growth pattern in the two other populations of A. zagrosensis . The condition factor varied from 0.74-0.93 in the populations. These information are vital in fisheries biology and could be used for species conservation and management.