The percentage of representation was characterised by good preservation of the pharyngeal bone (PR = 55.55 %) and the first vertebra (PR = 52.78 %) in cyprinids, the articular and the precaudal vertebrae in anguillids (PR = 16.67 % and 15.93 %) and the
opercle in clupeids (PR = 50 %).
Evolution of
opercle bone shape along a macrohabitat gradient: species identification using mtDNA and geometric morphometric analyses in neotropical sea catfishes (Ariidae).
Body covered in rough ctenoid scales; head entirely scaled, scales above dorsal opercular opening origin unorganized and very small, scales organized into loose rows on preopercle and
opercle, scales on snout, premaxilla, maxilla and lower jaw minute and unorganized.
Sides of head yellowish brown,
opercle golden yellow, scale borders brownish; black suborbital bar.
melanophores of caudal peduncle spot not conspicuous and restricted to just caudal peduncle) and by having the humeral spot extending on to the posterior part of the
opercle (vs.
After preservation, it was overall pale, with dusky areas on head, nape,
opercle, and on the dorsum at the base of the dorsal fin.
At the nest, the pair of red-eyed bronzebacks swim in a circle, with him frequently nipping at her
opercle, the bony covering protecting her gills.
The following sets of dimensions were taken: 1) Standard length: from tip of snout to base of caudal fin; 2) Head length: from tip of snout to posterior margin of
opercle; 3) Snout length: from tip of snout to anterior margin of orbit; 4) Predorsal distance: from tip of snout to anterior base of first dorsal ray; 5) Preanal distance: from tip of snout to base of anal fin insertion; 6) Length of base of adipose fin; 7) Caudal peduncle depth: shorter distance from caudal peduncle; 8) Head depth: taken at occipital region; 9) Body depth: at dorsal fin origin; 10) Orbital diameter: taken horizontally; 11) Interorbital width: taken between eyes; 12) Mouth width: width of lower jaw.
Five new species of genus Astyanax Baird & Girard, 1854 from Rio Iguacu, Parana, Brazil (Ostariophysi, Characiformes, Characidae)/ Cinco novas especies do genero Astyanax Baird & Girard, 1854 do Rio Iguacu, Parana, Brasil (Ostariophysi, Characiformes, Characidae) We initially identified Ammocrypta clara specimens from Elk River samples based on the presence of a well developed needle-like
opercle spine, one of several characters that differentiates A.
133: 0 [right arrow] 1, absence of adductor mandibulae Aw), with the genus Phractolaemus (249: 0 [right arrow] 1, mandible highly modified, the dentary bone being roughly perpendicular to the main body of the mandible), and with the genus Chanos (216: 0 [right arrow] 1, presence of prominent, thin, dorsally/anterodorsally oriented anterodorsal projection of
opercle).
Head reddish above, dark brown behind eyes and to posterior edge of
opercle, pale with dark spots below eyes, to pelvic-fin base; dark-brown, oblique bar from lower margin of eye with pale blue anterior to and below eye, and bright yellow spot immediately behind eye.