No bones about them, invertebrates don't have a spine. They proudly wear their skeleton on the outside (or stay wobbly and do not have one at all). With your help, Redmap will be tracking the following invertebrates around Australia. Some of these species may be common along your coastline - but have you spotted any that aren't normally found at your local diving, fishing or swimming spots? Redmap is interested in sightings where these invertebrates have ventured away from their usual home range. You can sort this list by region and name.

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  Western longspine sea urchin

  Centrostephanus tenuispinus

  The urchin is slate grey in colour with thinner spines relative to their length than the closely related black urchin. Length: Diameter …

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  Common sand crab

  Ovalipes australiensis

  The sand crab is readily recognised by the two red oval patches located towards the end of the light grey carapace. As its name suggests, …

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  Razor clam

  Pinna dolabrata

  Razorfish are the largest bivalve found in South Australia. They are fan shaped with its tip embedded in sand or mud, and are generally dar…

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  Blue swimmer crab

  Portunus armatus

  Blue swimmer crabs are generally distinguished by the long spine projecting from each side of the carapace and the fact that their last pai…

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  Eastern rock lobster

  Sagmariasus verreauxi

  This species is more common to New South Wales and is captured regularly in north-eastern regions of Tasmania in small numbers. Some fisher…

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  Giant cuttlefish

  Sepia apama

  The Australian giant cuttlefish is the largest cuttlefish species in the world reaching a total length of up to 1 m and a weight of 5 kg. M…