Salmoniformes

Salmoniformes View in CoL View at ENA ( Fig. 7 View Figure 7 )

In all three studied genera representing the three families in this order, i.e. Thymallidae , Coregonidae and Salmonidae , the configuration is similar: the lowest ray of the upper caudal lobe articulates with hypural 3 and the uppermost ray of the lower lobe articulates with hypural 2 ( Fig. 7A, B View Figure 7 ). In the diastema there are one or two CMCs ( Fig. 7 View Figure 7 ; see also Fig. 24A–I View Figure 24 ). The variation in number does not depend on the species. For example, our T. thymallus specimens were all from the same parents and raised under the same conditions; out of 14 specimens between 30 and 97 mm SL, five had one CMC and nine had two CMCs. If only one cartilage is present, it is large, ranging from half the height of the diastema to about as high as the diastema; it is roundish or triangular with blunt edges in lateral view and upright-oval when seen posteriorly. There seems to be no relation to fin rays.