Common name: Surf sardines, Surf silversides



Closely related to the Atherinidae, the family Isonidae comprises the genus Iso with five species, confined to the Indo-Pacific. A single species Iso rhothophilus occurs in Australia waters where it is found in the surf zone.

Surf sardines have a distinctive deep head and anterior that tapers to a slender caudal peduncle, pectoral fins inserted high on the body, usually two separate dorsal fins and a broad, silver mid-lateral stripe. Little is known of their biology.

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Cite this page as:
Bray, D.J. 2021, Surf sardines, ISONIDAE in Fishes of Australia, accessed 15 Jul 2024,


Bloom, D.D., Unmack, P.J., Gosztonyi, A.E., Piller, K.R. & Lovejoy, N.R. 2012. It’s a family matter: Molecular phylogenetics of Atheriniformes and the polyphyly of the surf silversides (Family: Notocheiridae). Molecular Phylogenetics and Evolution 62: 1025-1030

Campanella, D., Hughes, L.C., Unmack, P.J., Bloom, D.D., Piller, K.R. &  Ortí, G. 2015. Multi-locus fossil-calibrated phylogeny of Atheriniformes (Teleostei, Ovalentaria). Molecular Phylogenetics and Evolution 86: 8-23,

Saeed, B., Ivanstoff, W. & Aarn. 2006. Descriptive anatomy of Iso rhothophilus (Ogilby), with a phylogenetic analysis of Iso and a redefinition of Isonidae (Atheriniformes). Aqua, Journal of Ichthyology and Aquatic Biology 11: 25–43