| Summary: | 1. Invertebrate assemblages of tropical freshwater rock pools (FRPs) are poorly
known compared with temperate regions, where FRPs contain specialized,
endemic taxa of high conservation value. Invertebrates were sampled from pristine
FRPs in the Morgan River catchment in the Australian wet–dry tropics in the 2015
and 2016 wet seasons. Taxa were classified as either active or passive dispersers
and by functional feeding groups. A range of physical variables were examined to
identify associations with invertebrate assemblages.
2. Forty‐seven taxa were identified from FRPs; most were actively dispersing predatory insects, primarily Coleoptera and Hemiptera. Five adult insect species were
found in most pools; other taxa were rare and scattered across FRPs. Two previously undescribed species of Spinicaudata were collected, but few crustacean taxa
were recorded, and passively dispersing taxa were rare. Species accumulation
curves indicated that had more pools been sampled, more taxa would have been
collected in 2015, but in 2016 most species were collected.
3. There was no pattern in FRP assemblages related to any physical variable, but the
assemblages in pools were correlated between sampling times. An opportunistic
and mobile assemblage composed mostly of actively dispersing predatory insects
may explain the absence of relationships with measured variables. Low hydrological stability in the wet–dry tropics may be associated with low taxon richness.
4. The dominance of actively dispersing insects is in contrast with FRP assemblages
in temperate and arid regions. Studies of a wider range of FRPs from tropical
regions are required to determine whether the fauna of these Kimberley FRPs
are typical, and to fully describe short‐range endemic species across the Kimberley
and elsewhere.
5. The FRPs have conservation value as habitat for endemic, specialist rock‐pool
taxa, contributing to regional species pools. At present, a lack of knowledge of
endemic FRP specialist species in tropical regions, including the Kimberley,
impedes our ability to protect and conserve these species from disturbance.
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