SHORT BIGEYE IN WESTERN NORTH ATLANTIC 



105 



Pectoral-fin origin to midcaudal base. — Distance 

 from inner dorsal edge of base of most-dorsal 

 element of pectoral fin to base of midcaudal rays. 



Dorsal-fin and anal-fin origin to midcaudal 

 base. — Distance from anterior edge of base of first 

 spine of fin to base of midcaudal rays. 



Dorsal-fin and anal-fin termination to midcaudal 

 base. — Distance from posterior edge of base of 

 last soft -ray of fin to base of midcaudal rays. 



COUNTS 



Dorsal and anal spines.- — There are ten dorsal 

 and three anal spines, all clearlj- visible and 

 separate. Numbers are recorded in Roman 

 numerals. 



Dorsal and anal soft-rays. — Normally there are 

 1 1 dorsal and 10 anal soft-rays. The last soft-ray 

 of each fin, split to the base, was counted as one. 

 As the base of the penultimate soft-ray is often 

 very close to the base of the last split ray, its ray 

 should not be considered the anteriormost branch 

 of a doubly split soft-ray. Numbers are recorded 

 in Arabic numerals. 



Pectoral fin. — All rays in both fins were counted, 

 including rudiments. All are segmented, at least 

 in large adults (the most-dorsal segments at a large 

 size), and all but the most-dorsal and the two 

 most-ventral become branched. Numbers are 

 recorded in Arabic numerals. 



Pelvic fin. — It has a single spine, similar in 

 structure to spines of the vertical fins, and five 

 soft-rays (one of my specimens had four soft-rays 

 in one fin). 



Caudal fin. — The caudal fin has 16 principal 

 rays equally distributed between the two lobes, 

 as is characteristic in the familj- Priacanthidae. 

 All are segmented, and the innermost 14 are 

 branched. There is also a small number of 

 segmented secondary rays. 



Gill rakers. — Counts were made on the first 

 arch, usually on the right side. Rudimentar}- 

 gill rakers, often one or two occurring at the 

 origin of either limb, were included. A gill 

 raker located at the junction (angle) of the upper 

 and lower limbs was included in the count for the 

 lower limb. 



Pored lateral-line scales. — Only scales with a 

 complete tube were counted, usually on the left 

 side of the specimen, from the upper angle of the 

 opercular opening back to and including tiie scale 

 covering the base of the midcaudal rays. The 



lit 



several additional pored scales extending onto the 

 caudal rays were not counted. Sometimes the 

 tube system extended onto an adjacent scale 

 slightly above or below the main scale, but this 

 incompleteh' pored scale was not counted. Judge- 

 ment as to completeness of a tube may distort 

 the scale count by one or two scales. Counts were 

 considered the more accurate on larger specimens. 



Vertical scale rows.- — The number of anteriorly 

 oblique vertical scale rows was counted along the 

 midline of the bodj^ usually on the left side, 

 beginning at a point just below the anterior 

 terminus of the lateral line (counting from and 

 including the first complete scale on the cleithrum) 

 and continuing posteriorly to the base of the 

 caudal fin. Like the pored-scale row, several 

 vertical rows of scales continue onto the fin, and 

 the last row counted was the one which, when 

 visually extended anterodorsally, included the 

 last pored scale counted (the scale covering the 

 base of the midcaudal rays). Counts of the 

 number of rows on a fish may varj^ one or two 

 rows due to the sometimes irregular arrangement 

 of the rows, and counts made on larger fish were 

 considered the more reliable. 



Scales above and below lateral line. — Scales above 

 the lateral line were counted in an anteriorly 

 directed oblique line to the origin of the dorsal 

 fin, and those below in a posteriorly directed 

 oblique Une to the origin of the anal fin. Scales 

 are subject to crowding in the region adjacent 

 to the fins and the counts could not alwaj^ be 

 made accurately, except on the largest fish. 

 Pored lateral-line scales were not included in a 

 count. 



PIGMENTATION 



Descriptions of pigmentation represented in the 

 drawings and photographs were made from 

 microscopic observations of preserved individuals. 

 Chromatophores may have faded from some of the 

 smaller specimens, and descriptions of these 

 fish may be incomplete. 



DEVELOPMENTAL STAGES 



Larca/.— Defined as the stage of development 

 beginning with hatching and ending with forma- 

 tion of the adult complement of all fin rays, or in 

 P. alius when about 7-8 mm. A ray was con- 

 sidered to be completely formed when it became 

 partially ossified (determined by its staining red 



