Cycloid scale


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(Zool.) a fish scale which is thin and shows concentric lines of growth, without serrations on the margin.

See also: Cycloid

References in periodicals archive ?
Oblong scale shape is only present among the males while cycloid scale is in females.
periosus), by spiny scales surrounding the ear opening (versus cycloid scales) (Figure S12), and by the contact between the two greatly enlarged postmentals (versus enlarged lateral postmentals separated by small median postmentals) (Figure S13).
The main part of the body is covered with cycloid scales, but unlike females, males have also ctenoid scales on the head on the eye-side and on the trunk behind the head and close to dorsal and anal fins.
Scales on body progressively larger posteriorly, scale rows irregular, especially anteriorly; cheek fully covered with small scales; opercle naked except three scales at upper anterior corner; scales cycloid on head and anterodorsally on body, ctenoid posteriorly; scales ventrally on abdomen and chest cycloid; cycloid scales on pectoral-fin base; no scales on fins except for about three rows at base of caudal fin, smaller than last row on caudal peduncle.
Members of the Amiiformes Order, in which the Infraclass Teleostei is found, generally carry cycloid scales (Storer et al., 2007).
The development of the squamation of this actinopterygian fish begins on the body sides when the fish is less than 1 cm long, and soon, when it reaches 1 cm, the entire body is covered with cycloid scales. Ctenoid scales start to appear on the lower side of the caudal peduncle when the body is 1.40-1.42 cm long, and then appear more anteriorly, first ventrally then dorsally.
Scales small for the genus, progressively smaller anteriorly, extending on side of nape to above middle of opercle, but none in median predorsal zone or prepectoral area (if embedded scales are present in these two apparently naked areas, none could be dislodged); scales ctenoid posteriorly on body, becoming cycloid anterior to origin of second dorsal fin; small cycloid scales present on chest; no scales on fins except basal fourth to fifth of caudal fin.
Post-ingestion sample analysis revealed that the many bones and cycloid scales (Moyle & Cech 1988) found in the scat were identical to those of carp (Cyprinus carpio) examined from the SRSU vertebrate collection.
Cirrhitid fishes all have X dorsal spines, III anal spines, 14 pectoral rays (the lower five to seven rays unbranched and thickened), two flat opercular spines, a serrate preopercle, cycloid scales, one to several cirri at the tip of each membrane of the dorsal spines, and no swim bladder.
Scales: body completely covered with ctenoid scales, ctenii becoming larger posteriorly; predorsal region, cheek, operculum, pectoral fin base and pelvic fin base with cycloid scales; lateral scale rows 21(1), 25(4), 26*(2), 28(1); transverse scale rows 6(2), 7*(4); predorsal scales 7(1), 8(4), 9(1), 10*(2), scales extending anteriorly to behind eye; caudal peduncle scales 9(1), 10(3), 11*(2), 12(1); scales on cheek 3(4), 4*(2), 5(2); operculum scales 0*(4), 3(4); no modified basicaudal scales present.