Growth of tench (Tinca tinca L., 1758) (Cyprinidae) in reservoirs of K. Satpayev canal

The reservoirs of the K. Satpayev canal are the important fishery water bodies in the Central Kazakhstan. Some of these reservoirs are inhabited by tench, a fish species relatively widely represented in other water systems of the region. In the reservoirs of the canal this species is not the main commercial one but it has a fairly high commercial value due to its popularity with consumers. As part of the research, the growth indicators of Tinca tinca from 4 reservoirs were evaluated, and the data on its growth from 3 more reservoirs were also provided. These samples differ in efficiency and growth rates. It has been found that there is no sexual or generation variability. Growth rates in successive fish generations strongly correlate with each other, which may indirectly indicate the stability of living conditions. The R. Lee’s phenomenon was not marked. In this regard, the calculation of variables of the von Bertalanffy growth equation was carried out without additional data processing. The highest rates of linear growth were characteristic of Tinca tinca from the reservoir of HS No. 9. However, the effectiveness of its growth scheme was the lowest. Population with a longer age range from the reservoir HS No. 3 did not have high linear growth rates, but its growth efficiency was higher. In this case, it is obvious that any assessment of growth will be relative and depend on the goals set for it. In the reservoirs of the canal there are more or less similar conditions for tench populations living due to the specifics of its functioning. The main limiting factor for the growth rate, in our opinion, will be abundance of the species in the reservoir and related trophic factors with a certain influence of withdrawal (fishing, predators).

Growth parameters of Poecilia latipinna (Lesueur, 1821) (Actinopterygii, Poeciilidae) – an introduced species in brackish water of Wadi Al-Bahayes (Oman)

This work is one of the first studies on the growth of Poecilia latipinna outside its natural habitat. The objective of our study was to investigate the growth parameters of the population of P. latipinna, which is an alien species in Oman (Wadi Al-Bahayes). The population structure of P. latipinna in Wadi Al-Bahayes (Oman; 23°40′47″N; 58°11′36″E) was studied in June and August 2020, using 124 fish. In the course of this study, the number of individuals of each sex, age, weight and size composition were determined. In addition, the total length–weight relationship (LRW) was calculated, as well as the von Bertalanffy growth equation. The mean growth performance (phi prime) and the condition factor were calculated. Males accounted for 37.10% and females for 62.90% of the population. The length–weight relationship and the von Bertalanffy growth equation were W = 0.0214 × L 2.7889 R2 = 0.9212, Lt = 11.46 (1 − e −0.127 (t + 2.71)) for males and Lt = 14.51 (1 − e−0.072 (t + 3.98)) for females. The mean growth performance and the condition factor were calculated as 1.22 for males and 1.18 for females and 1.54 for all specimens. The study shows that the population of the species is characterized by a wide age range. Consequently, monitoring of this alien species is highly recommended.

Parameters of equations for group growth of golden king crab Lithodes aequispinus in the northern Okhotsk Sea

Growth of golden king crab in the northern Okhotsk Sea is considered. Parameters of von Bertalanffy growth equation were estimated using SLCA method (Shepherd's length composition analysis): the asymptotic carapace width W∞ was 252.0 mm for males and 165.3 mm for females; the growth rate K was 0.081 and 0.130, respectively. Relative increment per molt for males with carapace width of 116-154 mm was estimated as 11.6 % for the carapace width and 10.9 % for the carapace length. Directly determined (by tagging) dependence of males molt frequency on their size was approximated by logistic curve of molting probability with the threshold of 164 mm carapace width for 50 % probability of annual molt. Mean probability of annual molt for recruits was estimated as 87 %, for pre-recruits — as 92 %. Taking into account the data on increment per molt and annual molt probability, the growth curve for males had the parameters: W∞ = 296 mm and K = 0.073. The age of recruits was estimated as 9 years by SLCA approach and as 8 years on the results of tagging. The growth equations parameters were determined for the first time for golden king crab in natural habitat in the Russian waters. These results could be used in models and for theoretical studies of Crustacean life history.

Age, growth, and mortality of littlehead porgy, Calamus proridens, from southeast Florida coastal waters

Sectioned otoliths were used to age littlehead porgy Calamus proridens (n = 737) from southeastern Florida recreational fisheries. Otolith sections contained easily identifiable annuli and were reliable structures for aging littlehead porgy up to 11 yrs. Opaque zones were deposited from March to June (peaking in April). Littlehead porgy ranged from 1 to 11 yrs and 220 to 385 mm total length (TL). Body size relationships were TL = 1.09 FL + 16.06 (n = 3474, r2 = 0.95), FL = 0.87 TL – 1.15 (n = 3474, r2 = 0.95), W = 4.76 × 10 −5 TL2.80 (n = 6722, r2 = 0.86), and W = 1.2 × 10−4 FL2.71 (n = 3474, r2 = 0.90), where W is total weight (g) and FL is fork length (mm). Growth was not significantly different between two discrete geographic regions of Florida, and the von Bertalanffy growth equation was Lt = 335 (1 − e−0.41 (t + 2.13)) for all areas combined. The point estimate of natural mortality was M = 0.38, while age-specific estimates of M ranged from 0.60 to 0.41 yrs−1 for ages 1–11. Littlehead porgy were fully recruited to the headboat fishery by age-3 and catch curve analysis resulted in an estimate of total mortality Z = 1.08 for ages 3–7+. This study reports first estimates of life history parameters for littlehead porgy from Atlantic waters of the southeastern United States.

Estimating Age-Specific Natural Mortality for Sandfish in the Eastern Coastal Waters of Korea

To estimate age-specific natural mortality, we proposed an age-structured biomass model with an impulsive dynamical system. In the estimation of natural mortality, we considered growth rate and also reproduction rate, growth, and catch of sandfish, Arctoscopus japonicus. Assuming a linear relationship between observed values of the catch per unit effort (CPUE) and total biomass estimated by the age-structured biomass model, we estimated the age-specific natural mortality using the CPUE and catch data, from 1994 to 2009, for varying values of the assumed initial total biomass in 1994, by selecting the largest coefficient of determination (R2). We suggested the following empirical formula: Mi=qKL∞ln(eK(i+1−t0) − 1eK(i−t0) − 1), which estimated natural mortality of sandfish, and the derived age-specific natural mortality was significantly related to fecundity and growth. The parameters of von Bertalanffy growth equation and a logistic equation of maturity with total length were derived from the data of otolith and gonad analysis of female sandfish collected from 2005 to 2008 and from 2005 to 2006, respectively. We also conducted sensitivity analysis by varying the exponent in the inverse function of total length.

Age, growth and reproduction of the golden grey mullet, Chelon auratus (Risso, 1810) in the Golden Horn Estuary, Istanbul

Age, growth and reproduction biology of the golden grey mullet, Chelon auratus (Risso, 1810) have been studied in the Istanbul Golden Horn area. Fish length ranged from 13.4–46.8 cm, and age from 1–10 years, respectively. The sex ratio (female:male) was 1:1.08. The length-weight relationship was estimated as W = 0.0127L2.89, W = 0.0099L2.97 and W = 0.0156L2.82 for both sexes combined, females and males, respectively. The von Bertalanffy growth equation parameters were: L∞ = 57.52 cm, K = 0.1 year−1, t0 = −2.24 year for pooled data. The gonadosomatic index (GSI) values indicated the major spawning period was between August and November, and the minor spawning peak between March and April. The highest GSI values were observed in September. The length and age of sexual maturity were estimated as 26.2 cm and 4 years for males and 24.1 cm and 3 years for females.

GROWTH OF AMUR FLATHEAD ASP PSEUDASPIUS LEPTOCEPHALUS (PALLAS, 1776)

Linear and weight growth of amur flathead asp Pseudaspius leptocephalus is described on the base of the measurements data collected on the lower Amur (from Nizhneleninskoe village to the mouth) in 2004–2018, using von Bertalanffy growth equation. Age was determined for 2240 fish including 1061 females and 528 males. The main specific features of the amur flathead asp growth are the absence of sexual dimorphism in linear growth rate and the absence of the body length differences between females and males, except of the eldest fish. However, the sexual dimorphism is found for the weight growth. A compensatory growth is noted for the amur flathead asp. The amur flathead asp parameters have some geographical variability.

Population dynamic of Big Eye Scad (Selar crumenophthalmus Bloch, 1793) in Kwandang Waters-Sulawesi Sea

Big eye scad (Selar crumenophthalmus) is one of important small pelagic fish which is exploited in Kwandang waters-Sulawesi Sea. The exploitation of this species has been increasing every year. This research was carried out to study the growth, mortality and exploitation of bigeye scad in the Kwandang waters during January-November 2016. The von Bertalanffy growth equation was derived as Lt = 25.95(1 - e 1,01(t+-0.16374)) with length between 14.9 -26.4 cm FL (average length 18,64 cm). The size at first capture (Lc) was estimated as 18.69 cm. The total, natural and fishing mortality rates were assessed as 4.28, 1.90 and 2.38 year−1, respectively. The exploitation rate (E) of 0.56 per year indicates that the degree of harvesting leads to a more capture condition.. The management that must be applied is to reduce fishing efforts to 12% of the current situation and to consider temporarily closing fishing activities (closing season).

Somatic growth and age of selected commercial fish species of the Cullera Coast, Iberian Peninsula, south-east Spain

This work provides data on the somatic growth and age of selected commercial fish species of the Cullera Coast, Spain. The biological information available that permits responsible fishing management of these species is relatively scarce. This study was conducted in the Bay of Cullera, Spain (39º 12’to 38º 59’N, and 0º 09’to 0º 15’W); and selected benthic fish species were analysed that are frequently fished by trammel nets (mesh size 28-76 mm) at a maximum depth of 30 m. Maturity , age and growth of 63 torpedoes, Torpedo torpedo (L., 1758), 115 red scorpionfish, Scorpaena scrofa Linnaeus, 1758, 280 red mullets, Mullus surmuletus Linnaeus, 1758, 139 stargazers, Uranoscopus scaber Linnaeus, 1758, and 476 Portuguese soles, Dagetichthys lusitanicus de Brito Capello, 1868 were analysed. The data obtained in this study revealed that 50% of individuals of all the species reached sexual maturity at a TL (total length) of 20.0-36.5 cm and at an age of 2-6 years. The von Bertalanffy growth equation derived were: TL=37.0 (1 - e(-0.2(t + 0.33))); TL =31.5(1 - e(-0.38(t + 0.54))); TL =35.5(1 - e(-0.2(t + 2.08))); and TL =34.3(1 - e(-0.14(t + 2.16))) for S. scrofa, M. surmuletus; U. scaber and D. lusitanicus respectively.

Length weight relationship, growth parameter, and condition factor of caroun croaker Johnius carouna (Cuvier, 1830) in the Southern waters of Java

Caroun croaker (Johnius carouna) is one of demersal fishes which are commonly caught in the south of Java waters. This fish captured by trammel net, gillnet, danish seine and mini trawl. This study aims to determine length and weight relationship, growth parameter, length frequency distribution and condition factors of croaker fish caught in the south of Java waters. This study was conducted from January-December 2015 at the Cilacap Ocean Fisheries Port, Central Java. Data collected was total length (TL in mm) and weight (W in g) of caroun croacker fish. A total of 2141 of Caroun croaker was caught by mini trawl during the sampling periods. The result showed that the size of croaker fish caught by mini trawl ranged between 85-225 mm with an average was 143.7 mm. Length and weight relationship expressed by equation of W = 0.0062 TL3.2889 ( R2 = 0.9443). The growth pattern of croaker fish was allometric positive. The Von Bertalanffy growth equation of caroun croacker fish in south of Java waters was Lt =155 (1 - e -0.9(t+0.2127)) with the asymptotic length (L∞) =155 mm, growth coefficient (K) = 0.9 per year and the theoretical age croaker fish that was equal to (t0) = - 0,2127.