Feeding behavior of nauplii of the genus Eucalanus (Copepoda, Calanoida)

The goals of this and following studies were to describe how nauplii of related calanoid copepods gather and ingest phytoplankton cells, and to compare their feeding behavior with that of copepodids and adult females of the same species. Nauplii of the calanoids Eucalanus pileatus and E. crassus draw particles towards themselves creating a feeding current. They actively capture diatoms > 10 pm width with oriented movements of their second antennae and mandibles. The cells are displaced toward the median posterior of the mouth and then are moved anteriorly for ingestion. The nauplii gather, actively capture, and ingest particles using 2 pairs of appendages, whereas copepodids and females use at least 4 of their 5 pairs of appendages (second antennae, maxillipeds, first and second maxillae) to accomplish the same task. These nauplii are not able to passively capture small cells efficiently like copepodids and females because they lack a fixture similar to the second maxillae. Gathering and ingestion by late nauplii of E. crassus and E. pileatus require together an average of 183 ms for a cell of Thalassiosira weissflogii ( l 2 pm width) and 1.17 S fox Rhizosolenia alata (150 to 500 pm length). Although na.uplii of related species show little difference in appendage morphology, they differ markedly in feeding and swimming behavior. Their behavior is partly reflected in the behavior of copepodids and adult females.

[1]  N. Copley,et al.  Short‐term changes in the biology of a warm‐core ring: Zooplankton biomass and grazing1 , 1987 .

[2]  B. Frost,et al.  Grazing control of phytoplankton stock in the open subarctic Pacific Ocean: a model assessing the role of mesozooplankton, particularly the large calanoid copepods Neocalanus spp. , 1987 .

[3]  G. Paffenhöfer,et al.  Effects of concentration on the feeding of a marine copepod in algal monocultures and mixtures , 1986 .

[4]  G. Paffenhöfer,et al.  Capture of small cells by the copepod Eucalanus elongatus , 1986 .

[5]  G. Paffenhöfer.  Food ingestion by the marine planktonic copepod Paracalanus in relation to abundance and size distribution of food , 1984 .

[6]  R. Strickler.  Sticky water: a selective force in copepod evolution , 1984 .

[7]  G. Freyer.  Functional Ontogenetic Changes in Branchinecta Ferox (Milne-Edwards) (Crustacea: Anostraca) , 1983 .

[8]  J. C. Andrews.  Deformation of the Active Space in the Low Reynolds Number Feeding Current of Calanoid Copepods , 1983 .

[9]  G. Paffenhöfer,et al.  Modes of cell capture in calanoid copepods , 1983 .

[10]  J. Strickler,et al.  Calanoid Copepods, Feeding Currents, and the Role of Gravity , 1982, Science.

[11]  J. Strickler,et al.  Suspension-feeding by herbivorous calanoid copepods: A cinematographic study , 1982 .

[12]  M. Koehl,et al.  Copepod feeding currents: Food capture at low Reynolds number1 , 1981 .

[13]  L. Atkinson,et al.  The relation of concentration and size distribution of suspended particulate matter to hydrography in Onslow Bay, North Carolina , 1980 .

[14]  M. Alcaraz,et al.  Catching the algae : a first account of visual observations on filter-feeding calanoids , 1980 .

[15]  J. Strickler,et al.  Chemoreceptors and feeding in calanoid copepods (Arthropoda: Crustacea). , 1975, Proceedings of the National Academy of Sciences of the United States of America.

[16]  A. Fleminger.  Pattern, number, variability, and taxonomic significance of integumental organs (sensilla and glandular pores) in the genus Eucalanus (Copepoda, Calanoida) , 1973 .

[17]  T. E. Bowman.  The Distribution of Calanoid Copepods Off the Southeastern United States between Cape Hatteras and Southern Florida , 1971 .

[18]  T. Björnberg.  The Larvae and Young Forms of Eucalanus Dana (Copepoda) From Tropical Atlantic Waters 1) , 1967 .

[19]  A. Orr,et al.  On the biology of Calanus finmarchicus IX. Feeding and digestion in the young stages , 1956, Journal of the Marine Biological Association of the United Kingdom.