Tag Archives: Aquatic

Engaewa

 

Engaewa (3) (600x402)

Engaewa mounds at the edge of a creek.

Engaewa (2) (640x443)

Engaewa are small burrowing crayfish that occur in the south west corner of Western Australia. There are five species, each with a restricted distribution and with one species critically endangered.

Macroinvertebrates of south Western Australia’s salt rivers 6

Hydrophilidae Berosus discolor

There are several species of water scavenger beetles that are able to tolerate extremes of salinity. The larvae obtain their oxygen through abdominal gills and crawl on the stream bottom feeding on small midge larvae and crustaceans. The adults have heads that bend downward (deflexed) and club shaped antennae tucked under their eyes that help to break the surface film of the water when replenishing their air supply. The hairs on their hind legs assist the beetles to swim. The adults eat plants and organic debris.

Macroinvertebrates of south Western Australia’s salt rivers 5

Aedes (Ochlerotatus) camptorhynchus is a mosquito species that breeds in the brackish and saline water of estuaries, inland rivers and wetlands. The larvae have been collected from water over twice as salty as sea water (90 ppt). The pupae are short lived, hatching quickly into adults. The adults can travel quite long distances and are found throughout the year, however they are most common from March to December. They are capable of transmitting the Ross River virus.

Macroinvertebrates of south Western Australia’s salt rivers 4

The caterpillar from the moth Hygraula nitens lives and feeds on the aquatic plant, Ruppia sp. and has been found in saline water up to 50 ppt. It belongs to the family Crambidae which are a poorly known group of moths whose larvae live underwater. They construct a cylindrical case of plant material that can reach two centimetres in length. The adults are small triangular moths with cream, grey and brown markings. The grid squares are 1mm2.

Unidentified caddisfly larvae

This caddisfly larvae (Trichoptera: Hydroptilidae) appears to be restricted to a small stream west of Albany and was first collected in 2006. The cylindrical silk secretion case is unusual for southern Australian hydroptilids but common in the tropical north. Hydroptilids feed on microscopic algae.  The grid cells in the background are 1mm square.