Ibacus peronii
species of crustacean
Ibacus peronii, commonly known as the Balmain bug (often shortened to just bug) or butterfly fan lobster, is a species of slipper lobster. It lives in shallow waters around Australia and is the subject of small-scale fishery. It is a flattened, reddish brown animal, up to 23 cm (9 in) long and 14 cm (6 in) wide, with flattened antennae and no claws.
Description
In common with other slipper lobsters, Ibacus peronii has a broad, flattened body and a large carapace. The carapace is reddish brown, and reaches lengths of 2–10 centimetres (0.8–3.9 in), with the whole animal able to reach a length of 23 cm (9 in), and a width of 10–14 cm (3.9–5.5 in). The antennae are also long and broad, and the flattened form of the whole animal allows it to partly penetrate itself in soft substrates. They have five pairs of legs and no claws. Captured animals typically weigh around 120 grams (4.2 oz), but the weight can range from 80 to 200 g (2.8 to 7.1 oz).
Female Ibacus peronii grows faster and reaches larger sizes in comparison to male Ibacus peronii. The size of female Ibacus peronii is significant because there is a linear relationship between the fecundity and the carapace length.
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Datasets, specimens, observations and peer-reviewed methods provide the appropriate test for the technical claims summarized here. The source revision retrieved here is dated Jan 14, 2026. The linked authority identifier is Q2215329. None of the 0 selected statements returned an explicit reference.
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This entry incorporates text from “Ibacus peronii” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.