Determination of some population parameters of the veined rapa whelk (Rapana venosa) in the Central Black Sea

2014 ◽  
Vol 95 (1) ◽  
pp. 123-129
Author(s):  
Naciye Erdoğan Sağlam ◽  
Cemil Sağlam ◽  
Yeşim Demir Sağlam
Keyword(s):  
Black Sea ◽  
Growth Parameters ◽  
The Black Sea ◽  
Population Parameters ◽  
Length Frequency ◽  
Alternative Product ◽  
Mediterranean Mussel ◽  
Length Frequency Data ◽  
Rapa Whelk

The veined rapa whelk is one of the most important invasive species in the Black Sea ecosystem since the 1940s. Following its introduction to the Black Sea, it destroyed most of the bivalve populations, mainly the Mediterranean mussel and oysters. However, the veined rapa whelk has commercial importance for the Black Sea fisheries as an alternative product. In this study, we aimed to determine some population parameters of the veined rapa whelk based on indirect ageing through length–frequency data by using the Bhattacharya method. We collected 1704 specimens by dredging along the coasts of Samsun Province in the Central Black Sea in 2011 from June to November. The age of the population varied from 0 to 6. Von Bertalanffy growth parameters were estimated as L∞ = 112.35 mm, k = 0.310, t0 = −0.486 and W∞ = 243.94 g. Mean length and weight, length–weight relationship, mortality and exploitation rates were derived as L = 56.80 ± 0.36 mm, W = 45.67 ± 0.89 g, W = 0.0006 L2.719, Z = 0.96, M = 0.57, F = 0.39 and E = 0.40, respectively.

scholarly journals The first data on the population parameters and morphometry of Mesogobius batrachocephalus (Pallas 1814) (Family: Gobiidae) in the southern Black Sea

2021 ◽  
Vol 4 (2) ◽  
pp. 116-128
Author(s):  
Mehmet Aydın
Keyword(s):  
Black Sea ◽  
Growth Parameters ◽  
Average Length ◽  
Gonadosomatic Index ◽  
Total Mortality ◽  
Mesh Size ◽  
The Black Sea ◽  
Population Parameters ◽  
The Caspian Sea ◽  
Female Ratio

Knout goby, Mesogobius batrachocephalus Pallas, 1814, which belongs to Gobiidae, inhabits in the Black Sea, Sea of Azov, the Caspian Sea and the rivers that flow in these three seas. The major population parameters and morphometry of Mesogobius batrachocephalus from the coasts of the southern Black Sea were investigated in this study. A total of 641 individuals were sampled between January 2019 and December 2019 between the depths of 2 to 120 m depth by using a trammel net with a mesh size of 17-24 mm. The average length and weight values were calculated as 23.1 cm (5.3-34.0) and 130.1 g (1.34-377.54) respectively. The male to female ratio of the population was found as 1:0.91 (P>0.05). Age of sampled 641 individuals varies between zero and seven. For all the sampled individuals, the von Bertalanffy growth parameters were calculated as; L∞ = 38.2 cm, k = 0.245 year-1 and t0 = -1.873 year and the length-weight relationship was found as W = 0.0058 TL3.148. Total mortality (0.481), natural mortality (0.466), fishing mortality (0.015), growth performance index (2.55) and condition factor (0.913) were calculated. The maximum value of gonadosomatic index was reached in March. Average relative fecundity was found to be 118.3 eggs per g (78.9-234.5), while the average diameter of the eggs was found as 2733.0 µm ±221.18 (2287.1-3097.8). This study provides the first data on the population parameters and the morphometry of Mesogobius batrachocephalus. These data could contribute to the establishment of a sustainable management plan for fisheries resources in the Black Sea.

scholarly journals Population Dynamics of Mud Crab (Scylla serrata) in the Southeastern Coastal Region of Bangladesh

2006 ◽  
Vol 19 (1) ◽  
Author(s):  
M. ZAFAR ◽  
S.M. NURUL AMIN ◽  
M.M. RAHMAN
Keyword(s):  
Growth Parameters ◽  
Coastal Region ◽  
Scylla Serrata ◽  
Frequency Data ◽  
Population Parameters ◽  
Mud Crab ◽  
Length Frequency ◽  
Southeastern Part ◽  
Male And Female ◽  
Length Frequency Data

Population parameters of male and female Scylla serrata were estimated using FiSAT software with length-frequency data collected from different areas of Cox’s Bazar, southeastern part of Bangladesh (Chakaria Sundarban, Moheshkhali and Kutubdia channel) to evaluate the growth parameters, mortality rates and exploitation levels. Asymptotic length (L∝) was 105.9 mm and 105 mm, and growth co-efficient (K) was 0.28/yr and 0.36/yr for male and female S. serrata, respectively. The natural mortalities of S. serrata were 0.49/yr and 0.58/yr and fishing mortalities were 0.35/yr and 0.38/yr for male and female accordingly. Recruitment of this species into the fishery takes place throughout the year. The exploitation level for S. serrata was found to be 0.41 for the male and 0.39 for the female. This study showed that the stocks of male and female S. serrata were not under fishing pressure (E< 0.50) in the Southeastern part of Bangladesh.

Effect of individual variability on estimation of population parameters from length-frequency data

1998 ◽  
Vol 55 (11) ◽  
pp. 2393-2401 ◽  
Author(s):  
You-Gan Wang ◽  
Nick Ellis
Keyword(s):  
Growth Parameters ◽  
Growth Parameter ◽  
Individual Variability ◽  
Fish Stock ◽  
Frequency Data ◽  
Population Parameters ◽  
Length Frequency ◽  
The Moment ◽  
The Individual ◽  
Length Frequency Data

We consider estimation of mortality rates and growth parameters from length-frequency data of a fish stock when there is individual variability in the von Bertalanffy growth parameter Linfinity and investigate the possible bias in the estimates when the individual variability is ignored. Three methods are examined: (i) the regression method based on the Beverton and Holt's (1956, Rapp. P.V. Reun. Cons. Int. Explor. Mer, 140: 67-83) equation; (ii) the moment method of Powell (1979, Rapp. P.V. Reun. Int. Explor. Mer, 175: 167-169); and (iii) a generalization of Powell's method that estimates the individual variability to be incorporated into the estimation. It is found that the biases in the estimates from the existing methods are, in general, substantial, even when individual variability in growth is small and recruitment is uniform, and the generalized method performs better in terms of bias but is subject to a larger variation. There is a need to develop robust and flexible methods to deal with individual variability in the analysis of length-frequency data.

scholarly journals POPULATION DYNAMICS OF MALAYAN LEAF FISH (Pristolepisgrooti Blkr.) IN RANAU LAKE, SOUTH SUMATRA

2018 ◽  
Vol 24 (2) ◽  
pp. 125
Author(s):  
Sevi Sawetri ◽  
Subagdja Subagdja ◽  
Dina Muthmainnah
Keyword(s):  
Mortality Rate ◽  
Growth Parameters ◽  
Total Mortality ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Frequency Data ◽  
Length Frequency ◽  
Lake Ecosystems ◽  
Exploitation Rate ◽  
Length Frequency Data

The Malayan leaf fish or locally named as kepor (Pristolepis grooti) is one of important biotic components in Ranau Lake ecosystems. This study aimed to estimate population dynamic and exploitation rate of kepor in Ranau Lake, South Sumatera. The population parameters are estimated based on length frequency data which were collected in March to October 2013. Growth parameters and fishing mortality rates were calculated using FiSAT software package. The results showed that kepor’s growth was negative allometric, which tended to gain length faster than weight. Kepor population was dominated (42%) by individual length of 10.0 to 11.0 cm. Predicted length infinity (L) was 17.28 cm with high value of growth rates (K) of 1.4 year-1. The natural mortality rate (M) is 2.57 year-1, the fishing mortality rate (F) is 5.36 year-1 and total mortality rate (Z) is 7.93 year-1. The exploitation rate of Malayan leaf fish in Ranau Lake (E = 0.68 year-1) has passed the optimum score.  

scholarly journals Consorts of gastropod Rapana venosa (Valenciennes, 1846) in the Northern Black Sea. Part I: Porifera, Cnidaria, Bryozoa, Chordata

2017 ◽  
Vol 2 (2) ◽  
pp. 20-33 ◽  
Author(s):  
I. P. Bondarev ◽  
N. K. Revkov
Keyword(s):  
Surface Area ◽  
Coastal Zone ◽  
Black Sea ◽  
The Black Sea ◽  
Bottom Fauna ◽  
Depth Range ◽  
Shell Surface ◽  
Rapana Venosa ◽  
The Core ◽  
Rapa Whelk

Gastropod mollusk-invader Rapana venosa (Valenciennes, 1846) in the 1940s took a free ecological niche terminal predator in benthic communities of the Black Sea shelf and has become an important element of the ecosystem. The ability of rapa whelk to have a devastating impact on the biocenosis filter feeders determines the necessity of constant monitoring of this species populations’ state. The study of rapa whelk showed that the ecological role of this species is not limited to predation. Fairly large shell R. venosa is a solid substrate for alga, attached and restrictedly movable (sedentary) benthic animal organisms, among which mobile free-living forms sometimes find shelter. The aim of the work is to describe specific complex of epibiotic organisms formed on rapa-whelk shells, which is regarded as a consortium, where of R. venosa is the core. To study the consort community of R. venosa a sampling was made in 7 regions of the northern part of the Black Sea: 1 – Mamaia beach, Romania, 2 – the north-western part of the Black Sea (NWBS), Crimean sector, 3 – Sevastopol, 4 – Alupka, 5 – Yalta – Alushta, 6 – Karadag, 7 – the Kerch Strait. The sampling in the coastal zone (less then 15 m depth) was carried out by SCUBA and snorkel diving, deeper (up to 40 m) was used “Ocean-50”grab corer was used. Totally of 856 specimens of R. venosa were collected and analyzed. The main bulk of the material in the amount of 750 specimens of R. venosa was sampled in the coastal zone in Sevastopol vicinity (south-western Crimea) at the depth range of 1.5–10.0 m. The collection of the rapa whelk specimens was carried out totally and each specimen was placed in a separate plastic bag indicating the collection area, depth and biotope. Along with the mollusks sampling, visual observations and photographic fixation of hydrobionts in situ were carried out. Based on the research results the taxonomic list of rapa whelk epibiotic organisms was extended and for the first time the taxonomic composition of the mobile forms permanently or temporarily present in the R. venosa consortium was given. The first part of the investigation provides a list of rapa whelk epibionts taxa relating to four (Porifera, Cnidaria, Bryozoa, Chordata) of the seven detected Phyla with indication of sampling depths and bottom type and comments on the frequency of occurrence, the quantity and of their interaction with the consortium core. Phylum Porifera is represented by 1, Bryozoa – 3 Cnidaria – 2 and Chordata – 4 species. The drilling sponge Pione vastifica was found in all the investigated areas, except region 2 (NWBS), with a frequency of 20 to 90 % and the shell surface area damage was up to 100 % (average 30–35 %). Not numerous representatives of Cnidaria were found singly in the region 3 (Actinia equina) and in the region 5 (Diadumene lineata). Bryozoans are the most common group of animal-consorts of rapa whelk present in all the areas of our research. The frequency of their occurrence ranged from 10 to 100 %, the covering area of the shell surface was from 0 to 85 %. More than 90 % of the total surface area of rapana shell cover with bryozoans and their occurrence is in Cryptosula pallasiana. The second bryozoans’ species on development indices is Conopeum seurati, which was found in areas 3, 6 and 7, where the occurrence was up to 30 % and the coverage was up to 25 %. The other 3 species of bryozoans (Schizomavella auriculata, Bowerbankia imbricata, Hippothoa sp.) were found rarely. Representatives of Chordata – 2 species of ascidians (Botryllus schlosseri, Ciona intestinalis) and 3 species of fish (Diplecogaster bimaculata, Parablennius tentacularis, Scorpaena porcus) were recorded singly in regions 2, 3, 5. For the four Phyla of animal organisms considered the consorts list of R. venosa of the sandy bottom biotopes (10 species) is twice more numerous than that of the rocky eco-form (5 species). The organisms studied are of a different degree and nature of relations with the core consortium from commensalism to parasitism. Generalized information on periphyton and total coverage of rapa whelk shells with epibiotic complex is given. The results of the work show that in the Black Sea R. venosa has become an important element of the ecosystem, increasing biological diversity of the bottom fauna due to the formation of its own consortium complexes of epibiontic organisms.

Sign in / Sign up

Export Citation Format

Share Document