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).

Quantifying migratory capacity and dispersal of the invasive Tench (Tinca tinca) in the St. Lawrence River using otolith chemistry

The study of distribution and dispersal of invasive fishes is challenging during the early stages of invasion. Quantification of trace elements incorporated into fish hard parts represents an innovative technique for this task. Otolith chemistry has been used to describe fish stock structure, migratory behaviour and to support the management of several species. We used otolith chemistry to study the dispersal and population structure of Tench (Tinca tinca), an invader in the St Lawrence River. Tench movements throughout the invaded portion of the system were reconstructed using a Random Forests Algorithm. The results showed that, despite the presumed limited dispersal capacity of the species, Tench are capable of extensive migratory movements (up to 250 km). The variability in migratory patterns among individuals, including both short- and long-distance movements, supports a stratified diffusion. Such a strategy may explain the successful invasion of Tench in the St Lawrence River ecosystem. Our study represent a flexible framework for the study of Tench ecology in its invaded and native range, as well as for other freshwater invasive fishes.

Tench (Tinca tinca (Linnaeus, 1758)). Thematic bibliography

Purpose. Forming a thematic bibliographic list of publications on the morphological, ecological, physiological and biochemical characteristics of the tench (Tinca tinca L.), its cultivation and the state of its stocks in natural water bodies. Methodology. The complete and selective methods were applied in the process of the systematic search. The bibliographic core has been formed with the publications exclusively in Ukrainian and Russian from the fund of scientific library of the Institute of Fisheries NAAS of Ukraine. Practical value. The list may be useful for scientists, practitioners, students, whose area of interests includes the study of physiological, biochemical, ecological and other characteristics of cyprinids, in particular tench, as well as the restoration of its stocks. Key words: tench, reproduction, morphological, physiological and biochemical characteristics, fishing.

Skeletal Development and Deformities in Tench (Tinca tinca): From Basic knowledge to Regular Monitoring Procedure

Skeletal deformities reduce fish viability, growth, wellbeing, and feed efficiency but also degrade the consumer’s perception of aquaculture products. Herein, the skeletal development and the incidence of skeletal deformities in tench (Tinca tinca) reared in semi-extensive conditions has been described in detail for the first time. Larval skeletons were assessed through an acid-free double-staining procedure in 157 individuals, while 274 specimens at the juvenile stage were evaluated through X-ray analysis. The first skeletal structures to be formed were those related with breathing and feeding activities (e.g., Meckel’s cartilage and opercula) and were visible in larvae of 4 mm of standard length (SL). The axial skeleton was fully ossified in larvae of 12–17 mm of SL, and the caudal fin complex in larvae with 17–26 mm of SL. At the larval stage, no upper-jaw or opercula deformities were observed, while a low incidence (1–9%) of other severe deformities in the heads of the fish (e.g., lower-jaw deformities) were reported. The incidence of vertebral deformities in tench reared in natural ponds was considerable in larvae (54%) and juveniles (52%). Vertebral deformities (fusion and compression) were the most common deformities found in tench larvae (approximately 30%) and vertebral shape deformity in juveniles (around 10%), being mainly located in the caudal region. Thus, a regular monitoring of the skeletal deformities in tench might help to identify better rearing protocols and improve product quality sold at markets. Characterizing the skeletal development not only in semi-extensive systems such as artificial and natural ponds but also under intensive rearing conditions, seems vital for a sustainable and profitable European tench aquaculture.

Distribution and diversity of fish from Seyhan, Ceyhan and Orontes river systems

In this study, the current ichthyofauna of the Seyhan, Ceyhan and Orontes River drainages were presented and actual taxonomic positions of the species were assessed. Sixty-seven species belonging to 32 genera and 17 families of fishes were reported from these river drainages in Turkey and Syria. Acanthobrama centisquama and Tinca tinca could not be observed in the study area and Alburnus sellal and Esox lucius are recorded for the first time respectively in the Lake Gölbaşı (connected to the Ceyhan River) and Seyhan River.