BIOTIC

BIOTIC Species Information for Gammarus salinus

Researched by

Georgina Budd

Data supplied by

MarLIN

Refereed by

This information is not refereed.

Reproduction/Life History

Reproductive type

Gonochoristic

Developmental mechanism

Direct Development

Reproductive Season

Autumn to spring

Reproductive Location

Insufficient information

Reproductive frequency

Annual protracted

Regeneration potential

Life span

<1 year

Age at reproductive maturity

<1 year

Generation time

<1 year

Fecundity

Increases with female length

Egg/propagule size

Insufficient information

Fertilization type

Internal

Larvae/Juveniles
Larval/Juvenile dispersal potential	100-1000m	Larval settlement period	Not relevant
Duration of larval stage	Not relevant

Reproduction Preferences Additional Information

Leineweber (1985) sampled a population of Gammarus salinus over 15 months in the south-western Kattegat at Sangstrup Klint, Denmark and reported that Gammarus salinus most likely had two generations per year, mature females were found from late November to late July. However, in the Limfjord, Denmark, the population of Gammarus salinus was reported to only produce one generation between 1977-1978, despite the presence of egg bearing females throughout the year (Kolding & Fenchel, 1979). Juveniles were most numerous from April through to July, and in the warmer months between July and October a relatively stable population was attained. The main reproduction period occurred during the winter months, with 80% of the female population reported to be pregnant, the adult generation died in May.
During reproduction, the male carries the smaller female grasped by his gnathopods, a condition known as amplexus. The animals separate briefly to permit the final preadult moult of the female. Sperm transfer is accomplished quickly; the male twists his abdomen around so that his uropods touch the female marsupium (brood pouch) and sperm are swept into the marsupium by the ventilating current created by the female. Finally the pair separate (Rupert & Barnes, 1994). The eggs are brooded within a chamber, the marsupium, beneath the thorax, formed by shelf-like plates projecting inward from the thoracic coxae.
Kinné (1960) examined the effects of different temperatures and salinity on the incubation time of Gammarus salinus. At a temperature between 19-20 °C females attained sexual maturity (1st oviposition) 20-30 days after hatching; their average length (from tip of rostrum to base of telson) being 7-8 mm. Males reached maturity one or more weeks later than the females. The incubation time (period between oviposition and hatching) of the eggs depended largely on the temperature at which the females were maintained; < 14 °C incubation took over 15 days and decreased to 5 days at 20 °C. As in other amphipods Kinné (1960) found that the fecundity of females increased with length, with numbers of eggs varying in a clutch (Ruppert & Barnes, 1994).

Reproduction References

Leineweber, 1985, Kinné, 1960, Ruppert & Barnes, 1994, Kolding & Fenchel, 1979,