OTOLITH DESCRIPTIONS AND IMAGES
Order: CLUPEIFORMES
Family: Clupeidae
Species: Sardinops neopilchardus
Common names: Australian pilchard (sardine)
Previous nomenclature: Clupea neopilchardus, Sardinops sagax ocellatus
Material
Description based on otoliths of four specimens of 65–152 mm SL. Otolith catalogue reference 13.3P4, P7, P10 and P12. Catch locality Victoria. ID by RG.
Otolith description
Otolith very small, ovate. Dorsal margin irregular; ventral margin dentate; posterior margin bluntly rounded and entire. Sulcus groove very deep, heterosulcoid; opening ostial. Collum ranging from severely constricted to ill defined. Ostium larger than cauda. Ostium extends onto the rostrum. Crista superior and crista inferior distinct and ridge-like; crista superior less well developed over the cauda than over the ostium; crista inferior well developed along the entire sulcus and crenate on its dorsal surface. Rostrum elongate, robust and rounded. Antirostrum considerably shorter than rostrum but distinct, sometimes with an upturned end. Excisura present; angle acute. Dorsal area depression broad and narrow above ostium and collum. Ventral area depression absent with the crista inferior dominating the area.
Morphometry
SL = 32.07 OL1.35 mm
n = 24; Std Err Est = 0.057; R = 0.96;
Otolith length range = 1.9–3.15 mm (TMAG)
Mass = 6.43 × 10–6SL3.11 g
n = 29; R = 0.96;
Fish length range = 68–154 mm SL (TMAG)
Distribution and ecology
Southern Queensland through to Western Australia, and Tasmania (most commonly in Bass Strait); also New Zealand (Last et al. 1983); form large schools in temperate (summer) and subtropical waters (winter); reaches 250 mm in length (Edgar 1997).
Predator–prey information
Known prey of little penguin (Eudyptula minor) (Montague and Cullen 1987, Klomp and Wooller 1988, Gales and Pemberton 1990, Chiaradia et al. 2003), southern bluefin tuna (Thunnus maccoyii) (Coleman and Mobley 1984), yellowfin tuna (Thunnus albacares) (Coleman and Mobley 1984, Young et al. 2001), Australian fur seal (Arctocpehalus pusillus doriferus) (Hume et al. 2004), little black cormorant (Phalacrocorax sulcirostris) (Marchant and Higgins 1990), pied cormorant (Phalacrocorax varius) (Marchant and Higgins 1990), short-tailed shearwaters (Puffinus tenuirostris) (Montague et al. 1984), crested tern (Sterna bergii) and little tern (Sterna albifrons) (Higgins and Davies 1996). Undistinguished species of this Family are known prey of shy albatross (Hedd et al. 2001), great cormorant (Phalacrocorax carbo) and Caspian tern (Sterna caspia) (Marchant and Higgins 1990, 1996), crested terns (Chiaradia et al. 2002), white-fronted tern (Sterna striata), little tern (Sterna albifrons) and fairy tern (Sterna nereis) (Higgins and Davies 1996).
Otolith of Sardinops neopilchardus from a fish of 152 mm SL
Order: CLUPEIFORMES
Family: Clupeidae
Species: Spratelloides robustus
Common name: Blue sprat
Material
Description based on otoliths of one specimen of 72 mm TL. Otolith catalogue reference 13.1P23. Catch locality Victoria. ID by RG.
Otolith description
Otolith very small, ovate. Dorsal margin entire to gently lobed; ventral margin lobed to entire; posterior margin straight and entire. Sulcus groove heterosulcoid; opening ostial. Ostium extends along the rostrum and is larger than the cauda. Colliculum poorly defined and heteromorph. Collum indistinct. Crista distinct and ridge-like over ostium, but less well developed over cauda. Rostrum robust, elongate and rounded. Antirostrum short, broad and pointed. Excisura moderate; angle acute. Dorsal area depression narrow above collum. Ventral area depression absent.
Morphometry
TL = 54.33 OL1.02 mm
n = 23; Std Err Est = 0.0495; R = 0.94;
Otolith length range = 1.5–3.5 mm (TMAG)
Mass = 3.54 × 10–7TL3.67 g
n = 23; Std Err Est = 0.0867; R = 0.99;
Fish length range = 45–73 mm TL (TMAG)
Distribution and ecology
Southern Queensland through to Western Australia, and T...