The effect of food on the determination of sex ratio in Calanus spp.: evidence from experimental studies and field data

Irigoien, Xabier; Obermüller, Birgit E.; Head, Robert; Harris, Roger P.; Rey, Catherine; Hansen, Benni Winding; Hygum, Bent Hansen; Heath, Michael R.; Durbin, Edward G.

doi:10.1006/jmsc.2000.0960

Cited by 52 publications

(36 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Both laboratory studies (Irigoien et al 2000;Dur et al 2012) as well as field observations (Moraitou-Apostolopaulou 1972) imply the role of variability of sex ratio in governing the population dynamics of the copepod community, and hence, in the present study, it became an important tool to unfold the critical role they play in sustaining the population of the two dominant copepod species, A. plumosa and B. similis, in this dynamic estuarine ecosystem. In the seasonal scenario, the observation of the lower sex ratio during the period of higher abundance and vice versa clearly indicates the leaning of sex ratio towards female dominance during higher abundance.…”

Section: Discussionmentioning

confidence: 68%

Seasonal dynamics of the copepod community in a tropical monsoonal estuary and the role of sex ratio in their abundance pattern

et al. 2015

View full text Add to dashboard Cite

Background: As salinity is considered the prime "ecological master factor" governing the zooplankton distribution and abundance in estuaries, a spatio-temporal interactive approach was followed to assess whether the responses of the estuarine copepod community towards the salinity are always direct with a strong positive affinity or whether there exist any complexities in their interrelationship. The study, also for the first time, addressed the role of sex ratio in governing the abundance and the population structure of copepods in the tropical monsoonal estuarine system. Results: The ecological scenario in the Cochin estuary revealed that irrespective of the season, higher zooplankton abundance occurred in the mesohaline zone (MSZ; salinity 5-18) of the estuary, despite the pronounced spatial shift of the MSZ from the lower reaches of the estuary to upstream locations, in conjunction with the varying seasonal fluvial influx and marine water intrusion. In the case of the sex ratio of copepods, the seasonal scenario revealed that the dominant copepods had a lower sex ratio during the period of higher abundance, and a negative relation was observed between the abundance and the sex ratio of copepod species during most of the seasons. Conclusions: The preponderance of the mesohaline and euryhaline species of the copepod community formed the key contributing factor towards the maintenance of higher abundance in the MSZ of the estuary. The bias in the sex ratio towards females favored higher reproductive output, resulting in the higher abundance during the favorable pre-monsoon period.

show abstract

Section: Discussionmentioning

confidence: 68%

Seasonal dynamics of the copepod community in a tropical monsoonal estuary and the role of sex ratio in their abundance pattern

et al. 2015

View full text Add to dashboard Cite

show abstract

“…As a result, the sex ratio may change through the breeding season. In nature, the adult sex ratio can be determined by several other factors besides differential mortality rates; for example, environmental sex determination (ESD) governed by food conditions (Fleminger 1985;Korpelainen 1990;Irigoien et al 2000) or intersexuality (Gusmao and McKinnon 2009). The cost of breeding is a function of the mortality experienced in the 'time out' phase.…”

Section: Modelmentioning

confidence: 99%

Optimal mate choice patterns in pelagic copepods

2012

View full text Add to dashboard Cite

The importance of sexual selection for the evolution, dynamics and adaptation of organisms is well known for many species. However, the topic is rarely studied in marine plankton, the basis of the marine food web. Copepods show behaviors that suggest the existence of sexually selected traits, and recent laboratory experiments identified some selected morphological traits. Here, we use a 'life history-based' model of sex roles to determine the optimal choosiness behavior of male and female copepods for important copepod traits. Copepod females are predicted to be choosy at population densities typically occurring during the main breeding season, whereas males are not. The main drivers of this pattern are population density and the difference in non-receptive periods between males and females. This suggests that male reproductive traits have evolved mainly due to mate competition. The model can easily be parameterized for other planktonic organisms, and be used to plan experiments about sexual selection.

show abstract

“…Sex ratio is also influenced by environmental conditions. Conditions favoring faster development in the last nauplius stage may generally induce the development of males, and unfavorable conditions may produce more females (Takeda 1950, Alcaraz 1997, Irigoien et al 2000. Producing more females under unfavorable conditions may increase the critical density above that based on a 1:1 sex ratio (Fig.…”

mentioning

confidence: 99%

“…2). However, this strategy may allow for rapid population growth when conditions improve if the females have had a chance to mate in the interim and therefore to reproduce rapidly when food becomes plentiful, as demonstrated in field studies (Tande & Hopkins 1981, Osgood & Frost 1994, Irigoien et al 2000). …”

mentioning

confidence: 99%

Mating success and its consequences for population growth in an estuarine copepod

Choi¹,

Kimmerer²

2009

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

We conducted experiments on mating success of the estuarine copepod Eurytemora affinis in the San Francisco Estuary, USA. The experimental approach was to isolate virgin pairs (one male and one female) in containers varying in volume from 0.03 to 32 l for 2, 4, or 8 h. Mating was considered successful if viable eggs were produced by individual females subsequently incubated for up to 5 d. The experimental data were analyzed by fitting a 3-parameter model to the data to determine the volume search rate of males. Mating frequencies indicated a volume search rate for E. affinis males of 7.2 ± 4.0 l h -1 (172 ± 96 l d -1, 95% CL), about 20-fold higher than that for Acartia hudsonica previously determined by a similar method. A simple population model showed that the critical population density needed to maintain the E. affinis population can be well below the seasonally low abundance of this copepod in the San Francisco Estuary. The low critical density may allow population persistence in an estuary without the production of resting eggs. KEY WORDS: Copepod mating · Allee effects · Population growth · Volume search rate Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 377: [183][184][185][186][187][188][189][190][191] 2009 (Katona 1973, Griffiths & Frost 1976, van Leeuwen & Maly 1991, Yen et al. 1998. Increasing detection range increases the volume search rate, i.e. the volume searched by males for females per unit time (Kiørboe 2007), which, in turn, reduces the population density needed to prevent mate limitation (Choi & Kimmerer 2008).In the present study, we determined the volume search rate for males of the calanoid copepod Eurytemora affinis and assessed the consequences of this rate for population recovery from low abundance. E. affinis (~1 mm total length) is a dominant species in many temperate estuaries, usually inhabiting lowsalinity areas, and is often associated with the maximum turbidity zone (e.g. Hough & Naylor 1991, Peitsch et al. 2000, David et al. 2005). The copepod is also an important food source for macrozooplankton such as mysids and many estuarine-dependent fishes such as striped bass Morone saxatilis (Burkill & Kendall 1982, Meng & Orsi 1991, Thorp & Casper 2003. E. affinis is capable of producing resting eggs in response to environmental conditions such as temperature, photoperiod, and crowding (Ban & Minoda 1992, Ban 1992. Mating behavior and fertilization have been well documented (Heinle 1970, Katona 1973, Katona 1975. Mate finding in E. affinis is asymmetric in that the female produces a pheromone signal and searches primarily for food, whereas the male detects the pheromone and pursues the female (Katona 1973). It is not well understood, however, how this mating behavior relates to population growth (Kiørboe 2007) and, in particular, how dilute the population can become before it is unable to recover.In the San Francisco Estuary, Eurytemora affinis has historically been abundant and reproductively active throughout the year i...

show abstract

The effect of food on the determination of sex ratio in Calanus spp.: evidence from experimental studies and field data

Cited by 52 publications

References 39 publications

Seasonal dynamics of the copepod community in a tropical monsoonal estuary and the role of sex ratio in their abundance pattern

Seasonal dynamics of the copepod community in a tropical monsoonal estuary and the role of sex ratio in their abundance pattern

Optimal mate choice patterns in pelagic copepods

Mating success and its consequences for population growth in an estuarine copepod

Contact Info

Product

Resources

About