The shallow-living, benthopelagic copepod species Pseudocyclops xiphophorus Wells (R Soc Edimburg 67:1967), collected over a yearly cycle from the fouling material in the brackish water Lake Faro (North-eastern Sicily), showed marked seasonal fluctuations in population abundances, with maximum numbers recorded in autumn. Highest in situ egg production rates coincided with periods of low adult and juvenile densities and vice versa, except in autumn when peaks in egg production and adult population densities were coincident. In this period, mean daily egg production rates reached a maximum of 4–5 eggs per female, when surface water temperature was 17–18°C. Egg production rates declined drastically in winter and were completely arrested when surface temperatures dropped to 10–12°C. In March, daily egg production rates began to increase again with an increase in ambient temperatures, reaching a maximum at the end of August. In the laboratory, as in the field, mean daily egg production rates were positively correlated with temperature, with values ranging from 2.2 ± 0.3 (16°C) to 8.9 ± 2.6 (30°C) (mean ± S.D.) eggs per female per day. At 32°C, P. xiphophorus females survived but did not reproduce. At 34°C, all specimens died after a few days. In terms of total egg production for the entire female lifespan, maximum values occurred at 16°C and minimum at 24°C. Temperature also dramatically affected female life span, which was shorter at higher temperatures. Development time of eggs decreased with increasing temperature, as also development time from egg to adulthood. Remating was necessary for the continued production of fertile eggs at 16°C because female life span was longer. The unique egg-laying behaviour in this species may ensure higher survival rates of egg stages compared to free-spawning and egg-carrying calanoid species. After releasing the egg pair, the female swims over the eggs with a rotatory motion, secreting a substance which facilitates the adhesion of the eggs to the bottom; she then continues to swim over the eggs until they are attached. Although egg production rates in this species are low compared to other pelagic copepods, they are within the range of values reported for egg-carrying species. The greater fecundity at higher temperatures compared to other subtemperate species indicates that the species is well adapted to the higher temperatures of coastal lagoons and brackish water lakes where it contributes to the biofouling community.
Hatching Success Copepod Species Male Couple Pavlova Lutheri Brackish Water Lake
This is a preview of subscription content, log in to check access.
Durbin EG, Durbin AG, Campbell RG (1992) Body size and egg production in the marine copepod Acartia hudsonica during a winter-spring diatom bloom in Narragansett Bay. Limnol Oceanogr 37:342–360CrossRefGoogle Scholar
Genovese S (1963) Osservazioni preliminari sullo zooplancton degli stagni salmastri di Ganzirri e di Faro. Boll Pesca Piscic Idrobiol 1:1–12Google Scholar
Kiørboe T, Mohlenberg F, Hamburger K (1985) Bioenergetics of the planktonic copepod Acartia tonsa: relation between feeding, egg production and respiration, and composition of specific dynamic action. Mar Ecol Prog Ser 26:85–97. doi:https://doi.org/10.3354/meps026085CrossRefGoogle Scholar
Kleppel GS, Holliday DV, Pieper KE (1991) Trophic interactions between copepods and microplankton: a question about the role of diatoms. Limnol Oceanogr 36:172–178CrossRefGoogle Scholar
Laundry MR (1983) The development of marine calanoid copepods with comment on the isochronal rule. Limnol Oceanogr 28:614–624CrossRefGoogle Scholar
Marshall SM, Orr AP (1952) On the biology of Calanus finmarchicus. VII: factors affecting egg production. J Mar Biol Assoc UK 30:527–547CrossRefGoogle Scholar
Sullivan BK, Mc Manus LT (1986) Factors controlling seasonal succession of the copepod Acartia hudsonica and A. tonsa in Narragansett Bay, Rhode Island: temperature and resting egg production. Mar Ecol Prog Ser 28:121–128. doi:https://doi.org/10.3354/meps028121CrossRefGoogle Scholar
Tester P, Turner JT (1990) How long does it take copepods to make egg? J Exp Mar Ecol Prog Ser 52:7–16Google Scholar
Truper HG, Genovese S (1968) Characterization of fhotosynthetic sulfur bacteria causing red water in Lake Faro (Messina, Sicily). Limnol Oceanogr 13(2):225–232CrossRefGoogle Scholar
Zagami G, Costanzo G, Campolmi M, Granata A, Brugnano C (2003) Ciclo biologico del copepode Pseudocyclops umbraticus Giesbrecht, 1893 allevato in laboratorio. Biol Mar Mediter 10(2):273–275Google Scholar