Reproduction of meso- and bathypelagic chaetognaths in the genus Eukrohnia

  title={Reproduction of meso- and bathypelagic chaetognaths in the genus Eukrohnia},
  author={Makoto Terazaki and C. B. Miller},
  journal={Marine Biology},
Reproduction of meso- and bathypelagic chaetognaths, a major group of zooplankton and hermaphroditic animals, became clear after the microscopic examination of samples collected from the Pacific Subarctic Water. Species of the genus Eukrohnia carry their developing eggs in two marsupial sacs, one on each side, and the young are retained in these marsupia for at least some period after hatching. This is in line with a general trend for low fecundity, as care of the young increases. Almost all… 

Population structure and reproduction of Eukrohnia bathypelagica and Eukrohnia bathyantarctica in the Lazarev Sea, Southern Ocean

  • S. Kruse
  • Environmental Science
    Polar Biology
  • 2009
Cross-fertilization appears to be more common in both species, as most individuals developed testes and ovaries consecutively in Eukrohnia bathypelagica and E. bathyantarctica.

Growth and reproduction of the chaetognaths Eukrohnia hamata and Parasagitta elegans in the Canadian Arctic Ocean: capital breeding versus income breeding

This data indicates that as the Arctic warms, the development of an autumn phytoplankton bloom could favour the summer–autumn brood of P. elegans, and storage reserves contained in an oil vacuole may allow E. hamata to reproduce and grow outside the short production season.

The gonad maturation and size structure of the population of abundant planktonic predator Eukrohnia hamata (Möbius, 1875) (Chaetognatha) in the Eurasian basin of the Arctic Ocean in summer

The results indicate that E. hamata successfully matures and reproduces in the Arctic basin, but mature individuals make up less than 1% of the population in the summer against the background of juvenile abundance.

Calispadella alata n. gen., n. sp., the first chaetognath recorded from a hydrothermal vent site (Mid-Atlantic Ridge)

Calispadella alata n. gen., n. sp., is the first chaetognath described from a hydrothermal vent field (Mid-Atlantic Ridge, depth ∼1600 m). It belongs to the family Spadellidae (presence of transverse

Species composition, seasonal abundance and population structure of chaetognaths in Admiralty Bay (Antarctic)

Although chaetognaths inhabiting polar ecosystems are relatively well known, there are few reports on their functioning in the Antarctic coastal plankton community. The presented results provide the

Abundance and community structure of chaetognaths from the epipelagic through abyssopelagic zones in the western North Pacific and its adjacent seas

Relatively larger head width and longer hooks of deep- sea chaetognaths are considered to be an adaptation significant to the successful capture of prey zooplankton in resource limited deep-sea environments.

Reproductive strategies and energetic adaptations of polar zooplankton

Key factors governing polar ocean ecosystems are low temperatures and a pronounced seasonal variability of ice cover, light regime and primary production, and life-cycle strategies of the herbivorous copepods and euphausiids, which make up the major portion of polar zooplankton biomass, include seasonal vertical migration, dormancy and the accumulation of energy reserves.



Egg Pouches and Other Reproductive Structures in Pelagic Chaetognatha

Some specimens of Eukrohnia bathyantarctica David from the collections obtained by the United States Antarctic Research Program were observed which had marsupial sacs full of eggs, and hanging from


The act of copulation of a planktonic chaetognath which leads to successful insemination and fertilization consists of a behavioral sequence in which partners maintain contact at their head ends while engaging in violent movements which result in the transfer of spermatophores.

Population and Production Ecology of Zooplankton in Ogac Lake, a Landlocked Fiord on Baffin Island

Collections were analysed from the three basins of the lake in 1957, and from the middle basin of theLake Ontario and a fertilized polyethylene column in 1962 to identify the abundant copepod.

Resultados científicos do cruzeiro do "Baependi" e do "Vega" à Ilha da Trindade: Chaetognatha

The taxonomic results regarding the Chaetognatha collected during a voyage to the oceanic island of Trindade made in 1950 are presented, with a new species of the genus Pterosagitta besnardi, the second known of this genus.