Laboratory culture and life-cycle experiments with the benthic amphipod melita plumulosa (zeidler)

Abstract

In Australia, the collection of estuarine invertebrates from the field for whole-sediment toxicity tests is hindered because of temporal variability in their population densities and distributions. The present study aimed to develop culturing procedures for Melita plumulosa (Zeidler), an epibenthic and intertidal, deposit-feeding amphipod that is native to the southeastern coast of Australia. During a 28-d chronic exposure, the species was tested under a range of salinities (5-35 per thousand), temperatures (14-25 degrees C), and sediment particle sizes (sand to silt). Optimal culture conditions with respect to salinity, temperature, sediment particle size, feeding, and light regimes were determined. Compared to survival, amphipod growth and fertility were better predictors of optimal culture conditions. A life-history experiment was undertaken at the initial culture conditions of 22 degrees C and 35 per thousand salinity to establish the age at maturity, length of reproductive cycle, and life span for each sex. Under these test conditions, posthatch female M. plumulosa released their first offspring at seven weeks, after which each female produced an average of nine juveniles every 16 d. Male M. plumulosa had an average life span of eight months, whereas females had an average life span of 11 months. Optimal culturing conditions established in the present study have been incorporated into toxicity test procedures with this species and are being used to maximize reproductive output of this species in laboratory cultures to provide a supply of juveniles for routine use in whole-sediment toxicity tests.

Short-term accumulation of Cd and Cu from water, sediment and algae by the amphipod Melita plumulosa and the bivalve Tellina deltoidalis

“…Melita plumulosa were obtained from laboratory-maintained cultures originally established from organisms collected from intertidal mud flats at Brooklyn in the Hawkesbury River, north of Sydney. Procedures for maintaining cultures of M. plumulosa in the laboratory have been described previously (Hyne et al 2005). Tellina deltoidalis of 5 to 8 mm in length were collected during low tide from mud flats at Boronia Park, Lane Cove River, Sydney, Australia, during 2002 and 2003.…”

Toxicity to Melita plumulosa from intermittent and continuous exposures to dissolved copper

“…Sediment from the surface layer (top 2-4 cm) was scooped into two clean Zip-lock 1 bags using a clean stainless steel shovel, the bags were sealed, and the sediment was stored in a cool room for a maximum of 2 months before use. This sediment has been characterized in the past and found to contain relatively low sediment-bound and porewater contaminant concentrations and has been deemed suitable for culturing M. plumulosa [18,19].…”

“…The lids of the test vessels were loosely capped and aerated by continuously bubbling air (a tube was inserted through the lid into the test solution). The amphipods were fed small amounts of fish food (0.03 mg per amphipod, Sera Micron) at the start of the test and after each water change to prevent organism death resulting from starvation or stress [16,18]. The pH, salinity, temperature, and dissolved oxygen were measured at the start and end of each test and during each water change ($72 h).…”

It’s All in the Genes: How Genotype Can Impact Upon Response to Contaminant Exposure and the Implications for Biomonitoring in Aquatic Systems

“…Males are readily distinguishable from females by their larger gnathopod 2 as well as having more bristles along the antennae . Optimal culture conditions for this amphipod as established by Hyne et al (2005) are seawater of 25‰ salinity at 25°C ambient temperature on sediment composed of > 96% silt.…”

“…Studies have demonstrated this amphipod to be sensitive to both aqueous and sediment-bound metals and PAHs in both acute and chronic exposures, with juvenile animals displaying greater sensitivity than adult M. plumulosa Hyne et al, 2005;King et al, 2005Spadaro et al, 2008).…”