Family CIROLANIDAE Dana, 1852

Natatolana taiti

© Copyright from Keable 1997.

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• Cirolaninae Dana, J.D. 1852. On the classification of the Crustacea Choristopoda or Tetradecapoda. American Journal of Science and Arts 2 14(41): 297-316 [303] [original spelling; erected as subfamily of Aegidae].

Introduction

The Cirolanidae is the second-largest family of the aquatic Isopoda with 68 genera holding more than 591 species, of which 39 genera and 450 species (as of 10 August 2024) are marine or estuarine. The family is found in all marine and estuarine waters and is relatively well represented in fresh water, springs, caves and ground waters. Marine cirolanids occur worldwide, with highest diversity within the tropics, and are largely absent from polar waters. The family is dominated by four marine genera, ¬Cirolana Leach, 1818, Eurydice Leach, 1816 (on sand beaches and subtidal sands), Metacirolana Kussakin, 1979 (particularly on coral reefs) and Natatolana Bruce, 1981; these large genera comprise 76% of all marine cirolanid species. The family is near exclusively scavenging and predatory in feeding habits (see Bruce 1986; Brusca et al., 1995), with two species known to be commensals of other invertebrates, namely Cartetolana integra (Miers, 1884) which associates with crinoids, and Neocirolana hermitensis (Boone, 1919) which associates with hermit crabs of the genus Dardanus and is probably an egg predator. The scavenging species, which may occur in their thousands at times, play a probably important ecological role in marine environments from the intertidal to the upper continental slope. Cirolanids are generally scarce at depths greater than 500 m, and rare beyond 1000 m with 27 species (7%) known from depths of 1000 m or more, and of these only nine species are known from more than 2000 m depth.

Cirolanids are common marine and estuarine crustaceans. Freshwater species occur only outside Australia. They are frequently found on sandy beaches, rocky shores, coral reefs, and on shelf and slope environments where they are scavengers, predators or occasionally commensals. A considerable number of genera and species are known from cave waters (Botosaneanu et al. 1986), with three species recorded from such a habitat in Australia. Bruce (1986) reviewed an extensive literature on the ecology of cirolanids from many localities.

The history of the family and relationships between the numerous genera were discussed briefly by Bruce (1986). The keys in Bruce et al. (1982) and Bruce (1985, 1993) can be used to differentiate the family from the Aegidae, Corallanidae, Cymothoidae and Tridentellidae.

Over 100 species are known from Australia. They were reviewed in detail by Bruce (1986) who also listed all other species; more species have been added to the Australian fauna since. Kensley & Schotte (1989) recognised three subfamilies: Cirolaninae, Eurydicinae Stebbing, 1905, and Conilerinae Kensley & Schotte, 1989.

Diagnosis

Eyes widely separated, lateral, sometimes small or absent. Antennula peduncle 3-articled, flagellum and antenna with peduncle and flagellum distinct. Mouthparts not forming a buccal cone; mandibular incisor broad, tridentate, wider than 50% width (rarely less) of mandible body; lacinia mobilis indistinct or absent, spine row present; molar, large, bladelike, anterior margin usually toothed. Maxillula lateral endite with 10–13 acute, often keratinized, robust setae. Maxilla with 1 or 2 endites. Maxillipedal endite as long as palp article 1; palp of 5 articles. Pereopods 1–3 ambulatory with robust dactyli or sub-prehensile pereopods 4–7 ambulatory or natatory.

General References

Botosaneanu, L., Bruce, N. & Notenboom, J. 1986. Isopoda: Cirolanidae. pp. 412-422 in Botosaneanu, L. & Stock, J.H. (eds). Stygofauna Mundi. A Faunistic, Distributional, and Ecological Synthesis of the World Fauna Inhabiting Subterranean Waters (including the Marine Intersitial). Leiden : E.J. Brill & Dr. W. Backhuys.

Bruce, N.L. 1985. Calyptolana hancocki, a new genus and species of marine isopod (Cirolanidae) from Aruba, Netherlands Antilles, with a synopsis of Cirolanidae known from the Caribbean and Gulf of Mexico. Journal of Crustacean Biology 5: 707-716

Bruce, N.L. 1986. Cirolanidae (Crustacea: Isopoda) of Australia. Records of the Australian Museum, Supplement 6: 1-239

Bruce, N.L. 1993. Two new genera of marine isopod crustaceans (Flabellifera: Sphaeromatidae) from southern Australia, with a reappraisal of the Sphaeromatidae. Invertebrate Taxonomy 7: 151-171

Bruce, N.L., Brusca, R.C. & Delaney, P.M. 1982. The status of the isopod families Corallanidae Hansen, 1890, and Excorallanidae Stebbing, 1904 (Flabellifera). Journal of Crustacean Biology 2: 464-468

Kensley, B. & Schotte, M. 1989. Guide to the Marine Isopod Crustaceans of the Caribbean. Washington : Smithsonian Institution Press 308 pp.

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