and epihyal begin ossifying at 17 DPH followed by the ceratohyal and basihyal at 23 DPH.
Consequently, Rivulus was considered to be the sister group to a clade including "Rivulus" and all other rivulids, which was diagnosed by an apomorphic cartilaginous interhyal (vs.
Costa (1990), in a phylogenetic analysis based on morphological and behavioural traits, confirmed the presence of an ossified interhyal in some species then placed in Rivulus, but demonstrated that the number of seven pelvic-fin rays is not informative to define a rivulid clade.
cylindraceus, the type species of Rivulus, not available in the previous study, has a cartilaginous interhyal.
These were the sagittal otolith (OTO), as well as the interhyal (INTE), hypobranchial 3 (HYPO), pharyngobranchial 2 (PHAR), angular (ANGU), quadrate (QUAD), and the dentary (DENT).
Structure Species and structure code Grade n DCF SD Walleye pollock Interhyal INTE F 54 1.
QC3, quantification code 3, identified to family: basi-branchial, basioccipital, basipterygium, ceratohyal, coracoid, ethmoid, ectopterygoid, epihyal, exoccipital, frontal, hyomandibular, interhyal
, interopercular, lacrimal, lower hypohyal, opercular, opisthotic, otolith, palatine, prefrontal,' preopercular, prootic, pterotic, supracleithrum, scapula, supraoccipital, sphenotic, symplectic, urohyal, upper hypohyal.
Hyobranchial apparatus: Comprising median unpaired glossohyal, basihyal, three basibranchials and urohyal; and bilaterally paired dorsal and ventral hypohyals, anterior and posterior ceratohyals, interhyal, six branchiostegal rays, three hypobranchials, five ceratobranchials, four epibranchials and three pharyngobranchials (Fig.
Elongate interhyal bone forming in interhyal ligament between posterior ceratohyal and hyomandibula.
Bones included the angular (ANG), quadrate (QUAD), interhyal
(INTE), dentary (DENT), pharyngobranchial 2 (PHAR), and hypobranchial 3 (HYPO) (Fig.
2004, this issue) and included the sagittal otolith (OTO), as well as the interhyal
(INTE), hypobranchial 3 (HYPO), pharyngobranchial 2 (PHAR), angular (ANGU), quadrate (QUAD), and the dentary (DENT).