Brief description
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.Lineage
Statement: If the number of individuals caught in the beam trawl sample was less than 160, all individuals were sexed and measured but if the sample was greater than 160 then a sub-sample of 120 individuals was randomly selected. To determine the ash-free dry mass (AFDM), the total length of undamaged, preserved specimens from the beam trawl samples (sample size ranged from 4 to 44 per sampling date) were measured and then dried in an oven at 70 degrees for 3 weeks. Specimens were weighed to the nearest 0.001 grams and then ground with a mortar and pestle. Dried and ground tissue was combined into 8 replicates for both sexes of each species, which was approximately 0.01 grams or 30 to 50 individuals. Tissue samples were then ashed in a muffle furnace at 500 degrees for 8 hours. The mean percentage ash was calculated and the ash-free dry mass was obtained by subtracting this fraction from dry mass values. Productivity (P) was calculated using the equation P = sum of(N x M), where N = mean number of individuals in a cohort between sampling dates; and M = change in mean individual mass between sampling dates. Size-frequency distributions for each sampling date were used to determine the values for each cohort.Notes
CreditDr. Graeme Watson
Issued: 20 10 1981
Data time period: 1977-07-05 to 1980-01-14
text: westlimit=145.30; southlimit=-38.48; eastlimit=145.30; northlimit=-38.48
Subjects
28 756901 |
28 767018 |
28 770020 |
28 781018 |
63 619003 |
63 619004 |
BIOSPHERE |
Biosphere | Aquatic Habitat | Benthic Habitat | tidal flats |
Biosphere | Ecological Dynamics | Predation |
Biosphere | Vegetation | Flowering Plants | eelgrass |
Biosphere | Zoology | Invertebrates |
COMMUNITY DYNAMICS |
Community Structure |
Chlorotocella leptorhyncus |
EARTH SCIENCE |
ECOLOGICAL DYNAMICS |
ECOSYSTEM FUNCTIONS |
Heterozostera tasmanica |
Hippolyte caradina |
Macrobrachium spp. |
Oceans | Marine Biology | Marine Invertebrates |
Oceans | Marine Biology | Marine Invertebrates | Malacostraca | carid shrimps |
Population Dynamics |
Phillip Island |
Pontophilus candidus |
Rhyll |
SPECIES/POPULATION INTERACTIONS |
Trophic Dynamics |
Western Port Bay |
Zostera muelleri |
biota |
carid prawn |
carid shrimp |
eelgrass |
hump-backed shrimp |
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Other Information
global : 268431c0-f18e-11dc-aaae-00188b4c0af8
Identifiers
- global : 1ae1a280-fedb-11dc-8ac1-00188b4c0af8
