Libotonius: Difference between revisions

''Libotonius'' are small fish where adults range between {{cvt|10.6-40.0|mm|in}} long with narrow bodies and large heads. The [[premaxilla]] are narrower and longer in proportion then seen in ''Amphiplaga'', ''Erismatopterus'' and ''Percopsis'', and unlike those genera, it appears to lack a protrusion on the upper edge, the postmaxillary process. There are a reduced number of teeth in ''Libotonius'' species due to the [[Pterygoid bone|endopterygoid]], [[Pterygoid bone|ectopterygoid]] and [[Vomer#In other animals|vomer bones]] all being toothless, while the [[Palatine bone#Other animals|palatine]] is toothed. The vertebral skeleton is composedcomprised of between 38 and 43 vertebrae on average. The two dorsal fins have seven and ten rays, while the anal fins have an average of eight to ten. The pectoral fins have between 12 and 15 rays, contrasting the pelvic fin with one spine and seven rays. In the caudal fin the final two vertebra of the spine, the preural and ural centra are fused into one bone, a condition present in the other percopsids. The scales are round with concentric growth rings called circuli and up to thirteen [[fish scale#Ctenoid scales|ctenii spines]] on the rear margins.<ref name="Wilson1977"/><ref name="Wilson1979"/>

In overall size, ''Libotonius blakeburnensis'' is larger then ''L. pearsoni'' in [[Fish measurement|standard length]], thus the nose tip through the final vertebrae, but excluding the length of the caudal fin itself. ''L. blakeburnensis'' has a standard length ranging between {{cvt|30-40|mm|in}} long based on the described specimens in 1979. The total vertebral count of 33-34 is similar to ''L.pearsoni'' being an estimated two longer. The vertebrae are distributed into an estimated 15 [[fish anatomy|precaudal vertebrae]], between the skull and rear of the dorsal fin, and 18-19 [[caudal vertebrae]], between the dorsal fin end and the base of the tail complex. The precaudal vertebrae are further grouped as seven predorsal vertebrae in front of the dorsal fin, and eight precaudals with [[pterygiophore]] spines constitutingcomprising part of the dorsal fin. The dorsal fin has 2 to 3 spines and then 8-10 soft rays and the anal fin is similar with 2 spines and 8-9 rays. The pectoral fins have a greater number or rays, 13-15, than seen in ''L. pearsoni''.<ref name="Wilson1977"/><ref name="Wilson1979"/>