Sling-jaw wrasse

The reef fish, which is just over 50 cm long, is often colorful, variable in color (but not physiologically changing color) and also sexually dimorphic in its coloring. The species is protogynous (i.e. females can later become males). Juveniles are brown, but will soon get thin white stripes (illustration). Later some become completely yellow (xanthism), others remain mostly brown or have yellow spots; the pectoral fins are often dark. Males (from about 25 cm) are dark (brown) with a white head (with a dark band through the eye), later mostly with yellow-red spots on the back or the like; Spawning territoriality was observed. Several varieties have been described as "new species" (see figure). Epibulus brevis Carlson, Randall et Dawson 2008, on the other hand, is a real (second) species of the genus (established by Georges Cuvier in 1815). Fin formula: D IX – X / 9–11, A III / 8–9, P 12, C 11 (tail fin rounded, but with extended corners; sometimes almost black, or lighter than the trunk). 20–23 side line cycloid scales (corresponding to the number of vertebrae). 46 or 48 chromosomes (diploid). Jockstrap and maxillary apparatus (see fish mouth): The head profile is saddled in front of the eyes or hunched over. The lower jaw and premaxillary process (with Rostral cartilage) are very long: almost to the posterior margin of the skull; As a result, the pine handle is caudoventrally directed, as is the case with anchovies and many large-mouthed deep-sea fish (but mouth is not large, as with Stylephorus). The otherwise flat jockstrap is broken down into narrow, mutually movable elements. The maxillary apparatus is activated (as is sometimes the case) by lifting the upper skull (turning against the spine). A (paired) ligament from the vomer to the interoperculare (the only significant “innovation”!) Pulls this and thus the square and lower jaw forward; the premaxillary slides forward and the maxillary also swings forward, the mouth opens and becomes rounded. As soon as a "dead point" of the pre-stretching is overcome, the neurocranium is lowered again. The protraction or protrusion is directed forward and somewhat upwards. The negative pressure of suction is generated in the usual way by transverse expansion of the oral cavity, spreading the gill covers and lowering the hyoids. The jaw teeth are weak (only a few slightly larger teeth in the front; pharyngeal teeth but squeezing). The “mouth tube” is not folded differently from that of other maxillary apparatus. It is interesting, however, that Epibulus likes to visit cleaning stations and have his "tube" cleaned from the outside and inside, since the deep folds could give rise to foreign bodies or even parasites. At first it was thought that the fish "shot" like toxotes. HC Delsman (1925) provided the first explanations of protrusion (the protrusion of the mouth tube); the precise functional analysis of the mechanism comes from Westneat and Wainwright (1989).