Читать книгу Clinical Guide to Fish Medicine - Группа авторов - Страница 18

Skeletal bone may be cellular or acellular. Cellular bone is more common in bony fish. Acellular bone (without osteocytes) is seen in perch‐like fish (Percidae) and bass and sunfish (Centrarchidae). In both types, bones are typically solid and calcium absorption cannot occur locally; this means that fractures lack a local calcium reserve for repair. Fish lack bone marrow but there may be some vascular canals and spaces in the bone (Roberts and Ellis 2012). Hyperostosis or pachyostosis (also known as Tilly bones) has been documented in 22 fish families; the most common affected species in aquaria is Atlantic spadefish (Chaetodipterus faber) (Figure A1.2) (Smith‐Vaniz et al. 1995). Hyperostosis is not typically considered pathologic, but if the lesions get large, they may form sequestrae with associated skin ulcerations. Removal or rongeuring the bone underneath has helped resolve signs in some patients.

Teleost skulls are a complicated series of bones; anatomy varies significantly between species. Vertebrae also vary across species. Radiographically, vertebrae usually have a prominent cross that represents the conical recesses enclosing the intervertebral pad, a neural spine, a hemal arch (or pleural ribs cranially), and a hemal spine (Roberts and Ellis 2012). Ribs are either pleural (attached to vertebrae) or intermuscular (within muscular tissue) as in salmonids (Helfman et al. 2009).

Fin shapes and locations vary between species. They may be embedded in musculature or bone. Firm fin spines are common, particularly along the dorsal fin, and present a human health hazard. Some fin spines also contain venom, e.g. lionfish (Pterois spp.) and stonefish (Synanceiidae). Some fins are modified into suckers, e.g. lumpfish (Cyclopteridae). The lobe‐finned fish, lungfish (Dipnoi) and coelacanths (Latimeria spp.), have muscular fins with an articulating bone in their pectoral fin.

Figure A1.2 Radiograph of an Atlantic spadefish (Chaetodipterus faber) showing hyperostosis.