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| Titel |
Observations on the reproductive biology of two cyclopoid copepods: Oncaea media and O. scottodicarloi |
| VerfasserIn |
Georgios Fyttis, Monica Demetriou, Iole Di Capua, Yianna Samuel-Rhoads |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250110543
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| Publikation (Nr.) |
 EGU/EGU2015-10559.pdf |
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| Zusammenfassung |
| The small cyclopoid copepods Oncaea media and O. scottodicarloi are important
components of the zooplanktonic communities in the Mediterranean Sea due to their
numerical abundance and common distribution in coastal and open waters. However,
knowledge on their biology is still limited. The present study was aimed to acquire data on
their reproductive traits to highlight any difference between these two co-occurring oncaeids
that are very similar in size and morphology. Experiments were conducted in the laboratory
by monitoring groups of Oncaea ovigerous females (O. media + O. scottodicarloi) sorted
from zooplankton samples collected in February and March 2013 from coastal waters in the
inner Gulf of Naples (Tyrrhenian Sea, Western Mediterranean). The females were incubated
individually at in situ temperature (15 Ë C) in cell culture plates containing oxygenated
seawater with food particles that was changed every other day. The plates were inspected
daily under an inverted microscope to count the hatched nauplii and measure the interclutch
period, until all females were dead and subsequently identified as O. media or O.
scottodicarloi. Both species carry the eggs in two dorsal sacs where the eggs are
densely packed and cannot be precisely counted. The clutch size was therefore
estimated from egg sacs detached from ovigerous females sorted from the same samples
and fixed. The average number of eggs per sac was 35.2±6.6 (range 20-52) for O.
media and 24.4±4.5 (range 14-32) for O. scottodicarloi. Egg production rates (EPR)
were estimated to be on average 8.75 eggs female-1 day-1 for O. media and 6.15
eggs female-1 day-1 for O. scottodicarloi. The average egg development time was
8.05±3.78 days for O. media and 7.9±0.89 days for O. scottodicarloi. The interclutch
period for the females that produced new egg sacs was 2.2±1.3 days for O. media
and 3±2.7 days for O. scottodicarloi. The average recruitment of O. media was
7.6±3.7 nauplii f-1 d-1, with the minimum number of hatched nauplii being 4 and
the maximum 93. O. scottodicarloi recruited on average 6.5±4.4 nauplii f-1 d-1,
with the minimum number of hatched nauplii from one female being 17 and the
maximum 50. O. media and O. scottodicarloi differed significantly (p |
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