A combination of surveys and experiments were used to determine the size distribution, recruitment, mortality and growth rates 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). A size frequency distribution was constructed for each site from surveys that recorded the size of all individuals every 2 months from October 1979 to December 1981. In addition to the sites in Zone 1 there were 12 permanent quadrats (50 x 50cm) which were surveyed in the same manner from December 1980 to December 1981. The sizes of recruits were similar in both Zones but the sizes of adults were significantly greater in Zone 2. In both years, the maximum density of recruits in Zone 1 was greater than in Zone 2. The mortality rate of adult limpets in Zone 2 was lower compared to limpets in Zone 1. The growth rates (mm per month) of marked individuals were calculated for 3 time intervals; January-March, March-May and May-late July (Zone 2) and Mary-early August (Zone 1) in 1981. Limpets in Zone 2 grew faster (average 0.63 mm per month) than the limpets in Zone 1 (average 0.11mm per month). In addition, an experiment was conducted in Zone 1 from May to July in 1981 to determine the effects of adult density and macroalgal cover on limpet recruitment. It was found that there was no effect of adult density but a significant interactive effect of algal cover and sampling date on the number of limpet recruits.

This study surveyed the size distribution of Lepsiella vinosa at 3 sites on the rocky shore at West Head, Victoria. Monthly or bi-monthly searchers were conducted from June 1975 to August 1978 during spring low tide. Every individual L.vinosa found at the 3 sites was measured to the nearest 0.01cm with vernier calipers. To determine recruitment of L.vinosa to the shore, individuals were arbitrarily designated as juveniles (< 0.8 cm) or adult (> 0.8 cm). The type of microhabitat where each individual was found was recorded at Sites 1 and 2 for the searchers conducted in spring (November 1977), summer (January 1978), autumn (April 1978), and winter (August 1978). There were larger individuals of L.vinosa at higher intertidal levels (Site 1) compared to the mid- and lower sites (Sites 2 and 3). The recruitment of juveniles could not be determined from the size frequency distribution at any of the sites. There was more L.vinosa than expected in the rock pool habitats compared to the bare rock in all seasons except for winter at Site 2. There was high variability in abundance in the Lichinia habitat between all seasons and sites.

This study surveyed the size distribution of Lepsiella vinosa at 3 sites on the rocky shore at West Head, Victoria. Monthly or bi-monthly searchers were conducted from June 1975 to August 1978 during spring low tide. Every individual L.vinosa found at the 3 sites was measured to the nearest 0.01cm with vernier calipers. To determine recruitment of L.vinosa to the shore, individuals were arbitrarily designated as juveniles (< 0.8 cm) or adult (> 0.8 cm). The type of microhabitat where each individual was found was recorded at Sites 1 and 2 for the searchers conducted in spring (November 1977), summer (January 1978), autumn (April 1978), and winter (August 1978). There were larger individuals of L.vinosa at higher intertidal levels (Site 1) compared to the mid- and lower sites (Sites 2 and 3). The recruitment of juveniles could not be determined from the size frequency distribution at any of the sites. There was more L.vinosa than expected in the rock pool habitats compared to the bare rock in all seasons except for winter at Site 2. There was high variability in abundance in the Lichinia habitat between all seasons and sites.

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.

The ecology of 2 populations of the limpet Siphonaria diemenensis were investigated on the rocky intertidal shore at Griffith Point, San Remo, Victoria from 1979 to 1981. One population was on flat rock in the high intertidal area (Zone 1) and the other population was on the boulders in the low intertidal area (Zone 2). In Zone 1, there were 3 sites (combined area of 3.146 m2) and 12 permanently marked 0.25m2 quadrats and in Zone 2, there were 2 sites (combined area of 1.291m2). The population dynamics of the limpets were investigated by measuring shell lengths and dry weights of individuals in the 2 zones. Fences were used to enclose limpets or exclude limpets from areas of the substratum. Details of each experiment are described in the related records.

This study was conducted from December 1979 to December 1981 to determine the diet of Siphonaria diemenensis in the high and low intertidal zone on the rocky shore at Griffith Point, San Remo, Victoria. Gut contents analysis indicated that in both zones the limpets were feeding primarily on encrusting brown algae (e.g. Ralfsia verrucosa and Scytosiphon lomentaria). In an experimental manipulation, limpets were excluded from 15 x 15cm areas of rock to determine the change in algae cover in the presence and absence of limpets. Two runs of this experiment were conducted in Zone 1 from February to September and from September to December in 1980. The change in algae cover during the experiment was generally greater in the exclusion plots. This supports conclusions from the gut contents analysis, that encrusting brown algae form the major part of the diet of S.diemenensis. A growth experiment was conducted from 5 September to 15 November 1981 in Zone 1. There were 12 enclosures (15 x 15cm) with 15 limpets in each. Three enclosures were assigned to each of the 4 treatments; Ralfsia, Scytosiphon, scraped or bare. At the end of the experiment, 5 individuals were collected from each enclosure and their shell lengths and dry tissue weights measured. The mean shell length and dry tissue weights were greater in the Ralfsia and Scytosiphon treatments compared to the bare and scraped indicating that the presence of brown algae can be beneficial to this species of limpet. Algal abundances were monitored throughout this study by analysing photographs of permanently marked quadrats (50 x 50cm) at each of the study sites (3 sites in Zone 1 and 2 sites in Zone 2). Photographs were taken at monthly intervals from December 1979 to December 1981. In Zone 1, there was a clear seasonal trend in algae cover with a minimum cover in summer (January to March) and a maximum in spring (August to December). In Zone 2, there was no seasonal trend but a 100% cover of encrusting brown algae at all times. Individual adults were marked in both zones in April 1980 (42 in Zone 1 and 43 in Zone 2) and again in January 1981 (104 in Zone 1 and 66 in Zone 2) by cementing a small numbered label to the shell with a clear epoxy resin. The positions of marked individuals were measured regularly over a period of 8 weeks in 1980 and 1981. Over 70% of individuals were observed to home back to their original positions after 8 weeks with the remainder moving to new positions. Limpets were observed to begin to move at least 1 hour before being exposed to air on a receding tide, and to cease movement between 1 and 2 hours after they were uncovered.

Artificial substrata were used to investigate the patterns of establishment and change in the structure of a subtidal, marine epifaunal community at Portsea, Victoria from October 1975 to November 1979. Sessile invertebrate species and mobile species that significantly affected the distribution and abundance of the sessile species were the focus of the study. Experiments examining variability in recruitment and community development, species competitive ability, and the effects of predation on the epifaunal community at Portsea are outlined in the related records.

The population biology of the small predatory thaid gastropod Lepsiella vinosa was investigated on the rocky shore surrounding West Head, Western Port Bay, Victoria from June 1975 to December 1978. Details of the population dynamics, growth, reproduction, mortality, movement, and feeding of L.vinosa are described in the related records.

This study investigated seasonal variation in the abundances and size distribution of shrimp species in Western Port Bay, Victoria from July 1977 to January 1980. Four species, Macrobrachium intermedium, Pontophilus candidus, Hippolyte caradina and Chlorotocella leptorhyncus, were sampled using a beam trawl as described in the record 'The ecology and trophic role of caridean shrimps in the eelgrass community of Western Port, Victoria' (File identifier: 268431c0-f18e-11dc-aaae-00188b4c0af8). Individuals in each sample were counted, identified, sexed, size measured (total length, carapace length), and reproductive state of females noted. The relationship between body size and ash-free dry mass was obtained in order to calculate the standing crop and productivity of each species. M.intermedium was the numerically dominant shrimp species in the eelgrass. Mean densities of P.intermedius and H.cardian were 20-50% and 3-4% less abundant than M.intermedium, respectively. Maximum abundances of M. intermedium and P.intermedius occurred early in the year and coincided with the recruitment of large numbers of juveniles. Densities of H.caradina showed high variability between years. Low capture efficiency of C.leptorhyncus meant that this species was excluded from the analyses.

Study of the genetic structure, demography and recruitment of several species of marine invertebrates.