Neoscopelidae

Neoscopelidae View in CoL View at ENA ( Myctophiformes ) ( Fig. 20 View Figure 20 )

In Neoscopelus two CMCs are present, being less complex and smaller ( Fig. 20 View Figure 20 ) than in myctophids ( Fig. 19 View Figure 19 ). The upper CMC is positioned like a cap on the posterior-ventral edge of hypural 3. It is slightly bean-shaped when seen laterally, with its concave side facing the hypural edge ( Fig. 20A, B View Figure 20 ); when seen dorsally it is about one and a half times the width of a hypural plate and is cordate with its tip pointing caudally in between the bases of the lower ray of the upper caudal lobe. In posterior view the upper CMC is handlebar-shaped with enlarged rounded ends resulting in concave facets on the dorsal and ventral side ( Fig. 20C View Figure 20 ). This cartilage clearly supports the base of the lower ray of the upper lobe. The lower CMC is only slightly wider than the upper one ( Fig. 20C View Figure 20 ). In lateral view it is roundish with its ventral facet slightly flattened where it sits on the posteriordorsal margin of hypural 2 ( Fig. 20B View Figure 20 ). Seen from dorsal or posterior it is bar-like ( Fig. 20C View Figure 20 ). The upper ray of the lower caudal lobe articulates in the area where the lower CMC contacts hypural 2. There are no explicit medially directed pegs on the bases of the caudal fin rays present; only the dorsal margin of the base of the lowermost ray of the upper lobe bends peg-like medially towards the contact zone of the upper CMC with hypural 3. In the smaller of the two investigated specimens there was an additional, but very small cartilage anterior to the lower CMC, on the dorsal margin of hypural 2.