Therefore, the gill arches
from each side of the fish were numbered I, II, III, IV from the anterior gill arch
below the operculum to its posterior part.
The angle between the gill arch
and rakers changed from about zero to over 90[degrees], and therefore this angle is not regarded as an important character.
Similarly, it has been observed that the direct application of Nog regulates the BMPs in chondrogenesis, deducing that the activity of these proteins is increased when the antagonists decrease, and this increase reduces the expression of FGF-8 leading to improper migration of neural crest cells of the first gill arch
, causing stunt growth of the bones of the upper and lower jaws.
Gill opening broad, extending forward to vertical at posterior edge of orbit; gill membranes attached only anteriorly to isthmus, with no free fold; gill rakers slender, longest about equal in length to longest gill filaments of first gill arch
The number of gill rakers in the first gill arch
was significantly lower in S.
3), and the association is assumed to represent one individual for the following reasons: 1) all skeletal elements belong to the same taxon; 2) all gill rakers are within a size range found on a single gill arch
(Hovestadt and Hovestadt-Euler, 2011, p.
Next, the second right gill arch
was dissected, washed in saline buffer and immediately fixed in Bouin solution for 24h.
The research also showed for the first time that the gill arch
skeleton of embryonic skates (a living relative of sharks that has gill rays) responds to treatment with the vitamin A derivative retinoic acid in the same way a limb or fin skeleton does, by making a mirror image duplicate of the structure as the embryo develops.
The count of scales in longitudinal series is made from above the upper end of the gill opening to the base of the caudal fin; scales in transverse series are counted from the origin of the anal fin obliquely upward to the base of the first dorsal fin; the count of gill rakers is made on the first gill arch
, those on the upper limb given first.
The anterior trabeculae are formed from neural crest tissue, and they make up a portion of the visceral skeleton anterior to the mandibular gill arch
Without the progressionist assumption, the homeobox system might be seen as a necessary condition for the very existence of metazoa, and the gill arch
system as a necessary condition for the existence of vertebrates.
Counts included: dorsal fin spines and rays, anal fin spines and rays, pectoral fin rays, pelvic fin spines and rays, caudal fin rays, gill rakers on the first gill arch
, vertebrae, scales in lateral line, scales above lateral line, and scales below lateral line.
The monthly evolution of niche amplitude of each parasite species was calculated using the standardized index of Levins as follows [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] where Pj is the relative abundance of a given parasite species on the gill arch
48% in M arguni) and slightly higher number of rakers on the lower limb of the first gill arch
The second gill arch
was sectioned and fixed in a solution of 2.