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2. Effects of substrate composition and water temperature on the emergence success of lacustrine brown trout Salmo trutta m. lacustris L. fry from natural redds
- Creator:
- Radtke, Grzegorz
- Type:
- article, model:article, and TEXT
- Subject:
- spawning, redds, fry traps, survival, Salmo trutta, and the Trzebiocha stream
- Language:
- English
- Description:
- The emergence of lake-migratory brown trout Salmo trutta m. lacustris L. fry from natural redds was observed in a small lake outlet stream. A total of 1104 emerging fry were captured in traps in nine of the 12 investigated redds during three seasons. In 2005, all the fry emerged during the daytime, but in 2007 and 2009 they emerged mostly at night. Furthermore, the timing of emergence was earlier than expected from temperature models. The fry left the redds at a water temperature range of 6.2-15.0 °C, and the emergence pattern was correlated with the moon phase. The number of fry captured was strongly affected by the percentage of fine particles < 1 mm and the 8-16 mm particle content, and was positively correlated with the geometric mean of substrate particle size (Dg) and the index of permeability: the fredle index (fi). The estimated survival rate between egg deposition and fry emergence ranged from 0.0 to 59.8 % in individual redds. Additionally, the greatest number of fry and the highest survival rate were observed in redds that had the high water velocity and shortest duration of intragravel period.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Intimní život čichavce líbajícího
- Creator:
- Jaroslav Eliáš
- Format:
- bez média and svazek
- Type:
- article, text, články, journal articles, model:article, and TEXT
- Subject:
- Biologické vědy, biologie, ryby, výtěr ryb, rozmnožování ryb, fishes, biology, spawning, fish reproduction, labyrintní ryby, čichavcovití, noční tření, labyrinth fish, night time spawning, 2, and 57/59
- Language:
- Czech
- Description:
- Příspěvek se věnuje způsobu života čichavce líbajícího (Helostoma temminkii), jednoho ze zajímavých druhů labyrintních ryb. Popisuje způsob jejich života a také jejich využití. Jde o sladkovodní konzumní ryby, jejichž domovinou je jihovýchodní Asie. Své místo zaujaly také v akvaristice. Málo známý je i zajímavý způsob rozmnožování čichavce líbajícího chovaného v zajetí, který zachycují fotografické záběry při nočním tření., This article describes lifestyle and the use of the Kissing Gourami (Helostoma temminkii), one of the labyrinth fish. These edible freshwater fish native to south-east Asia are occasionally seen in aquaristics. The interesting way in which the Kissing Gourami breeds in captivity has only rarely been documented by photos because of its night time spawning., and Jaroslav Eliáš.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. Reproductive biology of Capoeta tinca in Gelingüllü Reservoir, Turkey
- Creator:
- Ekmekçi, Fitnat Güler and Özeren, Saniye Cevher
- Type:
- article and TEXT
- Subject:
- Central Anatolia, spawning, sexual maturity age, and gonadosomatic index
- Language:
- English
- Description:
- The breeding and sexual maturation properties of a cyprinid fish Capoeta tinca were studied in Gelingüllü Reservoir, a recently impounded dam in Central Anatolia. Ripening of gonads commenced in early spring, whereas spawning occurred between May and June. Sexual maturity age was 2+ for males and 3+ for females. The results obtained from this study were compared with those of other populations of C. tinca in Turkey.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
5. Reproductive biology of the marbled goby, Pomatoschistus marmoratus (Pisces, Gobiidae), in a northern Aegean estuarine system (Greece)
- Creator:
- Koutrakis, Emmanuil T. and Tsikliras, Athanassios C.
- Type:
- article and TEXT
- Subject:
- sex ratio, fecundity, spawning, and maturity
- Language:
- English
- Description:
- The reproductive biology of the marbled goby, Pomatoschistus marmoratus (Risso, 1810), was studied in the Strymon River estuarine system (northern Greece) between September 1997 and August 1999. Samplings were conducted on a monthly basis at the mouth of the river using a bag seine net and overall a total of 4 563 individuals were collected. The total length of males ranged between 2.5 and 6.0 cm and that of females between 2.8 and 5.7 cm, while that of unsexed individuals ranged between 1.2 and 2.9 cm. Sex ratio was 1.54:1 in favour of the females and statistically different from unity. The spawning of the species was extended, occurring between February and May. Mean absolute fecundity (F) was 1 386 (SE=8) oocytes and showed a significant positive exponential relationship with total length (F=14.387TL2.92), and total weight (F=1351TW0.83) of the fish. The relative fecundity ranged between 878 and 3 444 oocytes/g of total weight. Mean size at first maturity was estimated at 3.82 cm for the females and 4.66 cm for the males.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
6. Use of stream mouth habitats by Cottus perifretum and Leuciscus cephalus along the River Meuse (the Netherlands)
- Creator:
- Pollux, Bart J. A. and Kőrösi, Amikó
- Type:
- article and TEXT
- Subject:
- larvae, juveniles, nursery, resident, spawning, and transient
- Language:
- English
- Description:
- Size-frequency data were collected for two rheophilic fish species, Cottus perifretum and Leuciscus cephalus, at the confluences of 18 lowland tributaries along the regulated River Meuse (the Netherlands) between May 2004 and April 2005. Cottus perifretum is a resident species, using these stream mouth habitats throughout its entire life: i.e. as a spawning, nursery and adult habitat. Leuciscus cephalus is a transient species that uses these stream mouth habitats only as a temporary 0+ juvenile habitat during fall and early winter. This study suggests that the stream mouth habitats along the River Meuse fulfil different ecological functions for C. perifretum and L. cephalus.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/