Upward flexion of the
urostyle developed at 11.45 +- 0.42 mm (25 DPH, Fig.
The caudal skeleton had 3 epurais, the
urostyle, a small uroneural dorsal to the
urostyle, 4 hypurals, and 2 autogenous haemal arches on the antepenultimate and penultimate vertebrae.
Pale brown dorsum from tip of the snout to
urostyle, bearing large dark brown blotches on the posterior and medium part of back, becoming smaller on head (Fig.
Developmental stage refers to the upward (dorsal) flexion of the notochord tip (
urostyle) concurrent with caudal fin base and principal ray formation (Moser, 1996): the preflexion stage occurs when the notochord is straight; the flexion stage occurs when the notochord is obviously flexed and caudal rays are forming; and the postflexion stage occurs when the notochord tip is aligned vertically with the caudal base plate (hypural) elements.
Para-cloacal bands short and wide, extending from level of
urostyle to mid-length of thighs.
The following measurements were also included: internarial distance--distance between medial borders of nares; snout length--distance from tip of snout to anterior margin of eye; orbit-jaw distance--shortest distance between deepest region below eye and margin of upper jaw; naris-jaw distance--shortest distance between naris and margin of upper jaw; choana width--maximum width of choana; femur length--distance from tip of
urostyle to distal end of femur; arm length--distance from proximal end of radio-ulna to proximal base of pollex; hand length--length from proximal base of pollex to tip of third finger; interfascicular distance--shortest distance between dentigerous fascicles; and tarsal length--distance from proximal border of inner metatarsal tubercle to proximal end of tibiale.
Leap distances were determined by touching upright frogs at the base of the
urostyle, and measuring the length of the first leap made in response to the stimulus.
In preservation, two dark, slash-like pigments spots were present on the posterior lateral body above and below the
urostyle. In nearly all other aspects, juvenile finescale menhaden closely resembled adults by this size.