Brief description
A combination of surveys and experiments were used to assess the reproductive patterns of Siphonaria diemenensis in 2 zones on the rocky shore at Griffith Point, San Remo, Victoria. One zone was in the high intertidal (Zone 2) and one was in the low intertidal area on the shore. There were 3 sites in Zone 1 and 2 sites in Zone 2 (see parent record for more details).The breeding season of S. diemenensis was between August and May and spawning correlated with the phases of the moon. The numbers of egg masses at each site were recorded from regular searches during the breeding seasons in 1980-81 and 1981-82. The reproduction rates were highly variable between seasons in Zone 1 and less variable in Zone 2. It was suggested that the variation in reproductive rates between the different zones was correlated with changes in food availability.
An experiment was conducted to determine the reproductive effort of different sized individuals and to examine how responsive reproductive patterns are to changes in environmental conditions. On 18 August 1980, limpets were collected and placed within steel mesh enclosures (10x10cm). The enclosures were assigned to 8 different treatments groups (n=3). Details of the treatments are outlined in the attached resource. Egg masses were collected from the enclosures at regular intervals and at the completion of the experiment on 4 April 1981, 5 limpets were collected per enclosure. The shell length and dry weight was recorded for each limpet.
Lineage
Statement: REPRODUCTIVE CYCLE:Searches commenced in August of each year, before the first egg masses of the breeding season were laid, and finished in May of the following year at the end of the breeding season. The longest interval between searches was 7 day sand they were arranged to coincide with the predicted spawning cycles every fortnight.
REPRODUCTIVE EXPERIMENT:
A fourth enclosure for each treatment was also set up and limpets from this enclosure were used to replace any limpet that died in the 3 experimental replicates. The density of limpets in each enclosure was recorded every 2 weeks and missing individuals were replaced to maintain the appropriate density. The egg masses that were collected during the experiment were dried to a constant weight and ash-free dry weights recorded.
Notes
CreditLittlejohn, Murray, Dr
Purpose
The aims of this study were to (1) describe the reproductive cycle of Siphonaria diemenensis, (2) assess the importance of factors such as food availability in determining the patterns of reproduction and (3) estimated the reproductive output and reproductive effort of specific size individuals and the populations in Zone 1 and 2 on the Griffith Point rocky shore.
The aims of this study were to (1) describe the reproductive cycle of Siphonaria diemenensis, (2) assess the importance of factors such as food availability in determining the patterns of reproduction and (3) estimated the reproductive output and reproductive effort of specific size individuals and the populations in Zone 1 and 2 on the Griffith Point rocky shore.
Issued: 30 05 1985
Data time period: 1981-01 to 1981-12
text: westlimit=145.4; southlimit=-38.55; eastlimit=145.4; northlimit=-38.55
Subjects
24 488001 |
BIOSPHERE |
Biosphere | Aquatic Habitat | Benthic Habitat | rocky shore |
Biosphere | Ecological Dynamics | Competition | intraspecific |
Biosphere | Ecological Dynamics | Feeding Habitat | food availabiltiy |
Biosphere | Ecological Dynamics | Life History |
Biosphere | Zoology | Invertebrates |
EARTH SCIENCE |
ECOLOGICAL DYNAMICS |
Griffith Point |
Oceans | Marine Biology | Marine Invertebrates |
Oceans | Marine Biology | Marine Invertebrates | gastropoda | limpet |
Population Dynamics |
SPECIES/POPULATION INTERACTIONS |
San Remo |
Siphonaria diemenensis |
biota |
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Other Information
Description of treatments (Reproductive_Output_Exp.doc)
Identifiers
- global : a7cfbed0-eb16-11dc-bcdc-00188b4c0af8
