Bony fishes

From zero to ossified: Larval skeletal ontogeny of the Neotropical Cichlid fish Cichlasoma dimerus

“…At this stage, mainly the bones from the jaws, the ceratobranchial arches with their gill rakers and the pharyngobranchial and ceratobranchial toothplates, and the opercular complex evidenced some degree of ossification. Particularly, in cichlids, it has been proposed that the pharyngeal jaws are involved in food processing, whereas the oral jaws are more involved in food capture (Berkovitz & Shellis, 2017; Conith & Albertson, 2021). Thus, in resemblance to other teleost fishes, the first structures to start ossification in the cranial region belong to the splanchnocranium, whereas most of the bones from the neurocranium tend to ossify later and more slowly (Vandewalle et al, 1992, 1995; Wagemans & Vandewalle, 2001).…”

“…The present study showed that the urostyle ossifies as a single structure, placing C. dimerus in the first category. Regarding the development of the hypuralia, three variations of fusion have been described: five hypurals develop separately, but hypurals 1–2 fuse during ontogeny to form the lower hypural plate, and hypurals 3–5 show different degrees of fusion in some Atherinomorpha, clinids, mugilids, and pomacentrids; the lower and upper plates develop without a separate hypural precursor in blennids; and none of the five hypurals fuse during development in cichlids (Berkovitz & Shellis, 2017; Thieme et al, 2021; Woltering et al, 2018). Similar to other cichlids, C. dimerus did not evidence hypural fusion at least for the age and size range examined in the current study.…”