Life histories of some benthic insects from the La Trobe River, Victoria

Marchant, R.; Graesser, A.; Metzeling, Leon; Mitchell, Pat; Norris, RH; Suter, Phillip John.

doi:10.1071/mf9840793

Cited by 33 publications

(29 citation statements)

References 16 publications

(26 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Only in spring (for both the edge and riffle habitats) did the average number of taxa recovered from Live-sort sub-samples exceed that from the Lab-sort sub-samples, so the efficiency of the Livesorting method in recovering taxa appears to depend on the season in which a sample is collected. Many insect taxa have seasonal life-cycles, and distinct changes in the size distribution of the aquatic larvae occur with time (Marchant et al, 1984;Yule, 1985;Dean & Cartwright, 1987). Many such insect larvae are represented by small early instars in autumn, but in spring they are more mature and, therefore, more conspicuous (Hynes, 1970).…”

Section: Discussionmentioning

confidence: 98%

River condition assessment may depend on the sub-sampling method: field live-sort versus laboratory sub-sampling of invertebrates for bioassessment

Nichols

Norris

2006

Hydrobiologia

View full text Add to dashboard Cite

Aquatic macroinvertebrates are commonly used biological indicators for assessing the health of freshwater ecosystems. However, counting all the invertebrates in the large samples that are usually collected for rapid site assessment is time-consuming and costly. Therefore, sub-sampling is often done with fixed time or fixed count live-sorting in the field or with preserved material using sample splitters in the laboratory. We investigate the differences between site assessments provided when the two sub-sampling approaches (Livesort and Lab-sort) were used in conjunction with predictive bioassessment models. The samples showed a method bias. The Live-sort sub-samples tended to have more large, conspicuous invertebrates and often fewer small and, or cryptic animals that were more likely to be found in Lab-sort samples where a microscope was used. The Live-sort method recovered 4-6 more taxa than Lab-sorting in spring, but not in autumn. The magnitude of the significant differences between Live-sort and Lab-sort predictive model outputs, observed to expected (O/E) taxa scores, for the same sites ranged from 0.12 to 0.53. These differences in the methods resulted in different assessments of some sites only and the number of sites that were assessed differently depended on the season, with spring samples showing most disparity. The samples may differ most in spring because many of the invertebrates are larger at that time (and thus are more conspicuous targets for live-sorters). The Live-sort data cannot be run through a predictive model created from Lab-sort data (and vice versa) because of the taxonomic differences in sub-sample composition and the sub-sampling methods must be standardized within and among studies if biological assessment is to provide valid comparisons of site condition. Assessments that rely on the Live-sorting method may indicate that sites are 'less impaired' in spring compared to autumn because more taxa are retrieved in spring when they are larger and more visible. Laboratory sub-sampling may return fewer taxa in spring, which may affect assessments relying on taxonomic richness.

show abstract

Section: Discussionmentioning

confidence: 98%

River condition assessment may depend on the sub-sampling method: field live-sort versus laboratory sub-sampling of invertebrates for bioassessment

Nichols

Norris

2006

Hydrobiologia

View full text Add to dashboard Cite

show abstract

“…In addition, the seasonal temperature variation provides well defined cues for stream biota, and recruitment is often synchronous (Bunn 1988). Hydrology also plays an important role in shaping life histories (Resh et al 1988) and those of Australian stream invertebrates seem to be strongly influenced by the pattern of stream discharge (Marchant et al 1984;Bunn 1988).…”

Section: Introductionmentioning

confidence: 99%

Population dynamics and life history of Paratya australiensis Kemp, 1917 (Decapoda: Atyidae) in upland rainforest streams, south-eastern Queensland, Australia

Hancock¹,

Bunn²

1997

Mar. Freshwater Res.

View full text Add to dashboard Cite

Aspects of the life history and population dynamics of Paratya australiensis were examined in headwater streams of the Conondale Range, south-eastern Queensland, particularly in relation to spatial and temporal variation in temperature and flow dynamics. Breeding period and population structure at nine sites in three subcatchments were examined during three years of monthly sampling using a non-destructive, photographic method. Breeding was restricted to the warmer months of late spring and summer. Peak abundances of ovigerous females and release of larvae occurred earlier at warmer, lower-altitude sites than at cooler, upper-altitude sites. This is consistent with the general trend for seasonal breeding in temperate and subtropical species of atyids, and perennial breeding in tropical species, and suggests that the summer breeding period of P. australiensis was strongly influenced by temperature. In subtropical, south-eastern Queensland, larvae were released just before and during the wet season. Although populations were quite resilient, disturbance from high-flow events also shaped the life history. Hydrology modified the breeding period by influencing overall abundance and recruitment success and by favouring the early release of larvae before peak flows. The reasonably well defined seasonal cycle and synchronized development appear to result from the combined effects of temperature and hydrology.

show abstract

“…The harshness and uncertainty of the climate, together with the absence of a well-defined input of energy in the form of an autumn litter-fall, were considered to be indirectly responsible by giving rise to flexible life history patterns and broad niches of the species (Williams & Wan, 1972 ;Hynes & Hynes, 1975 ;Winterbourn, 1980) . Subsequent research, particularly in south-eastern Australia, has clearly demonstrated a highly seasonal litter-fall (Lake, 1982 ;Bunn, 1986a) and life histories that are perhaps more synchronized than previously thought (Marchant et al, 1984a ;Yule, 1985 ;Dean & Cartwright, 1987) . Furthermore, it is now evident that the fauna of these streams is not as depauperate as first suggested and may even be richer than comparable temperate Northern Hemisphere streams (Lake et al ., 1985).…”

Section: Introductionmentioning

confidence: 99%