Age, Growth, Reproduction and Fecundity of Roach Rutilus rutilus from Volvi Lake, Northern Greece

The roach, Rutilus rutilus, is a Cyprinid which is widely distributed throughout freshwater systems in Europe. It is one of the most abundant and important commercial fish species in Greece. Age, growth, reproduction and fecundity of roach were studied in Lake Volvi from 1997-1998 females had higher growth in length (L∞=277.18 mm, k=0.097) than adult males (L∞=185.60 mm, k=0.148). All males older than one year and larger than 70 mm, and all females older than two years and larger than 80 mm were sexually mature. The breeding period spanned from the end of March till mid April. Fecundity ranged from 2,036 to 31,653 eggs (mean 8,102 eggs) and relative fecundity from 76.06 to 333.94 eggs/g (mean 186.78 eggs/g). Diameter of eggs were 1.3 ± 0.07 mm and weighted 0.0011 ± 0.0002 g . The weight of eggs were independent of length and age of individuals (P>0.05), however, there was a significant relationship between weight and egg diameter (P<0.05). Absolute fecundity depended on length, weight and age of the females. The relationship between absolute fecundity and length were less obvious in the case of relative fecundity and egg size. Estimated growth was at the lower end when compared with other studies conducted elsewhere.

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Thermal effects on the seasonal dynamics of Paradiplozoon homoion (Bychowsky & Nagibina, 1959) parasitizing roach, Rutilus rutilus (L.)

Journal of Helminthology ◽

10.1017/s0022149x0000883x ◽

1989 ◽

Vol 63 (2) ◽

pp. 93-101 ◽

Cited By ~ 10

Author(s):

Johan Höglund ◽

Jan Thulin

Keyword(s):

Relative Density ◽

Nuclear Power ◽

Rutilus Rutilus ◽

Artificial Lake ◽

Roach Rutilus Rutilus ◽

Temporal Shift ◽

Total Prevalence ◽

Heated Area ◽

Host Mortality ◽

One Year

ABSTRACTThe prevalence and relative density of the monogenean Paradiplozoon homoion, were monitored over one year in populations of roach, Rutilus rutilus, captured in a thermally raised artificial lake located outside a nuclear power station and in a nearby reference locality. Recruitment of P. homoion started earlier in the warmer lake. A temporal shift of the life-cycle was thus observed but there were no differences between the total prevalence or the total relative density of the parasite in the two areas. Since there is no evidence of parasite-induced host mortality, or for the development of protective immunity, the main regulatory process in the heated area are most likely an increased mortality due to reduced thermal tolerance of the adult parasite.

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Length-Weight relations and condition factor of roach Rutilus rutilus (Linnaeus, 1758) in Lake Volvi (Northern Greece)

Acta Adriatica ◽

10.32582/aa.60.1.5 ◽

2019 ◽

Vol 60 (1) ◽

pp. 53-60

Author(s):

Stavroula Kyritsi ◽

Antonis K. Kokkinakis

Keyword(s):

Condition Factor ◽

Rutilus Rutilus ◽

Fish Growth ◽

The Other ◽

Northern Greece ◽

Roach Rutilus Rutilus ◽

Significant Difference

Length-weight relations (LWRs) and different indices of condition factor for roach from Lake Volvi (Northern Greece) were estimated. Results showed that roach are heavier of a given length in Lake Volvi than in other areas worldwide, with females exhibited higher weight than males of the same length. Significant differences (P<0.05) of LWRs were also exhibited between sexes depending on month. CLARK condition factor peaked at the end of summer displaying no significant difference between sexes, whereas the other three estimated condition factors (Allometric, FULTON, LE CREN) peaked in winter. The estimation of different proxies of condition factor disaggregated by sex might reduce the uncertainty raised by the estimation of fish growth.

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Sex hormones changes in blood and their effect on fecundity of African catfish (Clarias gariepinus Burchell, 1822) after being injected with different doses of human chorionic gonadotropin (HCG) hormone

Journal of Zoological Research ◽

10.30564/jzr.v2i4.2189 ◽

2020 ◽

Vol 2 (4) ◽

Author(s):

Hamed H.E. Saleh ◽

Ahmed E. Semaida ◽

Sayed R.S. Zidan ◽

Ramadan M. Abou-Zied ◽

Sobhy M. Allam

Keyword(s):

Sex Hormones ◽

Chorionic Gonadotropin ◽

Human Chorionic Gonadotropin ◽

Clarias Gariepinus ◽

Control Group ◽

African Catfish ◽

Relative Fecundity ◽

Absolute Fecundity ◽

Egg Diameter ◽

Different Doses

This study was conducted to investigate the effect of different doses injection of human chorionic gonadotropin (HCG) hormone on fecundity and serum sex hormones (FSH, LH, estrogen (E2), progesterone (P4), testosterone (T)) of African catfish (Clarias gariepinus). African catfish spawners were intermuscularly injected with different doses of HCG (500, 1500, 3000, 6000 IU/kg female), and group is not injected as a control; males were injected at half the female dose. The results showed that, fish group injected by 6000 IU HCG/ kg female had the highest gonadsomatic index, absolute fecundity and relative fecundity, while, the lowest value of absolute fecundity and relative fecundity were recorded with 500 IU HCG/ kg female. The group injected with the highest amount of HCG (6000 IU/ kg female) recorded the lowest value from egg diameter, while the highest egg diameter was observed in 500 IU HCG/ kg female. In females, the group injected with 6000 IU HCG/ kg female reflected the lowest level of FSH and the highest level of LH and the highest level of P4 compared to other treatments. Level of T recorded the highest level with 1500 IU HCG/ kg female. The control group reflected the highest level of FSH and E2, while the control group reflected the lowest level of T and P4 level. In males, serum FSH, LH, P4 and E2 in male groups injected with HCG were relatively higher than those recorded in the control group. The highest level of T was recorded in treatment injected with the highest dose of HCG and decreased in other treatments until recorded the lowest level of T in the control group. It was observed, HCG hormone has successfully and accelerate induced spawning in African catfish (Clarias gariepinus) and increased in reproductive performance with the increase in HCG dosage and as compared to group not injected.

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