© Baker, J.L. (2009) Marine Species of Conservation Concern in South Australia Full citation Baker, J.L. (2009) Marine Species of Conservation Concern in South Australia: Volume 1 - Bony and Cartilaginous Fishes. Report for the South Australian Working Group for Marine Species of Conservation Concern. J. Baker (consultant); Science and Conservation Division, and Coast and Marine Conservation branches of S.A. Department for Environment and Heritage (DEH); Marine and Coastal Community Network of S.A. (MCCN), and Threatened Species Network (TSN). Web version published by Reef Watch, South Australia.

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BYTHITIDAE: BROTULAS and BLINDFISH

(Drawing from Waite, 1921. Reproduced by University of Washington Libraries, Freshwater and Marine Image Bank)

Fishes in the Bythitidae, a family of live-bearing (viviparous) fishes, are similar to those in the Ophidiidae, with which they were previously included (Gomon, in Gomon et al., 1994; Nielsen et al., 1999). Bythitid fishes occur in the Atlantic, Indian, and Pacific oceans. Most species are from marine waters, but some species occur in brackish and fresh waters (Froese and Pauly, 2007).
Bythitid fishes have internal fertilisation and associated copulatory structures, which is unusual in fishes. Most species attain a small maximum size, and have a large mouth, reduced ventral fins, and elongate dorsal and anal fins, which are sometimes connected to the caudal fin (Gomon, in Gomon et al., 1994).  Species within the family that are commonly called Blindfishes are rarely blind.  Although some species have non-functional eyes because they live in total darkness, most are sighted, and use their eyes to swim around in the open at night-time (B. Hutchins, W.A. Museum, pers. comm., 2006).
Many members of the family occur in deep water; however a sizeable number occur on shallow waters, on rocky reefs (Gomon, in Gomon et al., 1994).
Of the 39 known genera (Froese and Pauly, 2007), at least 6 of these are found in southern Australian waters (Gomon, in Gomon et al., 1994). In recent years, a number of new species have been recognised, particularly from the Indo-Pacific and West Atlantic. Møller et al. (2003) reported two new genera and 26 new species (including 7 new species of Ogilbia), from an ongoing revision of the American bythitid fishes, based on about 1500 museum specimens. There are now more than 160 species recognised in the family.
Globally, there were 8 bythitid fishes on the IUCN Red List in 2007, most of which are found as small populations in particular freshwater caves and sinkholes, including Ogilbia pearsei (Vulnerable). The marine species O. galapagosensis is also listed (Data Deficient) (IUCN, 2007).
Two shallow water species known from South Australia and other southern States are included in synopses below - Dermatopsis multiradiatus and an undescribed species of Dinematichthys (Nielsen, pers. comm. to M. Gomon, Museum of Victoria, 2006).
The shallow-water bythitid fish, Monothrix polylepis (Ogilby, 1897) from eastern and southern Australia, has been recorded from One Tree Island in Queensland to Jervis Bay (N.S.W), and reportedly also from Spencer Gulf to Kangaroo Island in South Australia (Paxton et al., 1989, cited in Froese and Pauly, 2007). However, the South Australian material may represent a distinct species, in the Dinematichthys (Nielsen, pers. comm. to M. Gomon, Museum of Victoria, 2006). Another shallow-water species, the Eastern Yellow Blindfish Dermatopsis macrodon, has been recorded from Queensland and N.S.W., and also found off mainland New Zealand, and Lord Howe Island (Paxton et al., 1989; Kuiter, 1993, 1996b; Francis, 1993, cited in Froese and Pauly, 2007). In the Sydney area, the species has been recorded as a transient one, present occasionally, in rock pools (Silberschneider and Booth, 2000).

Associated taxa

Slender Blindfish / Yellow Eelpout	Dermatopsis multiradiatus McCulloch and Waite, 1918
Southern Pygmy Blindfish	Dactylosurculus gomoni Schwarzhans and Moller, 2007 (prev. Ogilbia sp., in Gomon et al., 1994)