DBPapers
DOI: 10.5593/SGEM2015/B32/S15.094

THE REPRODUCTION BIOLOGY OBSERVATIONS AT PONTO-CASPIAN RELICT AMPHIPODA SPECIES (PERACARIDA, CRUSTACEA)

V. Schroder
Thursday 24 September 2015 by Libadmin2015

References: 15th International Multidisciplinary Scientific GeoConference SGEM 2015, www.sgem.org, SGEM2015 Conference Proceedings, ISBN 978-619-7105-37-7 / ISSN 1314-2704, June 18-24, 2015, Book3 Vol. 2, 715-722 pp

ABSTRACT
This study tries to identify and clarify some of the problems regarding the reproduction biology of ponto-caspian crustacean species. These are the relict endemic species, from lakes and the Black Sea littoral waters, with the most important adaptations and evolutiv implications.
The study was made on amphipoda species (Dikerogammarus villosus, Pontogammarus borceae, Pontogammarus robustoides, Echinogammarus trichiatus, Echinogammarus warpachowskyi, Echinogammarus sowinskyi, Euxinia sarsi, Euxinia maeotica, Obesogammarus crassus).
Therefore were evaluated: the incubation period, the reproductive capacity, the fecundity potential, the correlation index (HMFBL-half-range of mature female body length), the life cycle model. The eggs have been removed from 489 females that belong to different categories of size, counting a total of 5,782 eggs.
For the species of the Romanian waters, the data obtained from the observations show the same variability within the species with the same dimensions and habitat (Dikerogammarus villosus, Pontogammarus robustoides, Echinogammarus trichiatus), also within females from the same species and the same category of size.
When HMFBL index is

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0.34 the number of laying downs is larger during the reproduction period (iteroparity).
Amphipods live 6-12 months a year while they have 4-5 generations. These data observed in the nature were also confirmed in laboratory conditions at Echinogammarus trichiatus and Euxinia maeotica. The life cycle model, duration of incubation, the interval between moulting and the juveniles’ survival were monitored in the experimental conditions for brackish Euxinia maeotica amphipods.
The information are important as they may improve the knowledge and understanding of the implications of them invasive capacity, especially the adjustment of the populations and predictability of new extension potential.

Keywords: crustacean, amphipoda, ponto-caspian, reproduction, life cycle