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Fishery Bulletin 108(3) 
Figure 2 
Adult Citharichthys gymnorhinus from the western North Atlantic Ocean. 
(A) Male; North Carolina State Museum (NCSM) 47657; 49.5 mm standard 
length (SL); featuring secondary sexual dimorphisms in cephalic spina- 
tion, wider interorbital space and black blotches on dorsal and anal fins. 
(B) Female (NCSM 47662; 39.3 mm SL) lacking cephalic spination or black 
spots on dorsal and anal fins, and with narrower interorbital space. Note 
also the elongate, pigmented ovary. 
region of the body. Adult C. gymnorhinus (Gutherz and 
Blackman, 1970; Topp and Hoff, 1972; this study) and 
C. cornutus (Parr, 1931; Gutherz and Blackman, 1970; 
this study) feature distinct sexual dimorphisms that 
facilitate macroscopic determination of sex of matur- 
ing and mature individuals of both sexes. Female C. 
cornutus lack dimorphic sexual features characteristic 
of male C. cornutus (compare Fig. 1, A and B), includ- 
ing the absence of rostral and cephalic spines, in hav- 
ing a much narrower interorbital space (usually <eye 
diameter), and females lack the dusky blind-side pig- 
mentation observed in recently captured males (taken 
off North Carolina). Females also have a different size, 
shape, and extent of posterior elongation of the gonad 
compared with that of males. In mature females, the 
ovary is broadly triangular anteriorly, extends posteri- 
orly for more than one-half the standard length of the 
specimen (see mature ovary in females in Figs. IB and 
2B), and is easily seen through the abdominal wall (vs. 
males with much smaller, rounded testes that do not 
undergo posterior elongation). For male C. gymnorhinus 
(Fig. 2A), secondary sexual characters include rostral 
and cephalic spination, conspicuous black blotches on 
dorsal and anal fins, dusky blind-side pigmentation 
(best observed in recently caught males), an elongate, 
fragile first fin ray (often broken) in the ocular-side 
pectoral fin, and small, rounded testes without poste- 
rior elongation. These features become conspicuous in 
some males between 29 and 35 mm SL and are well 
developed in all males >42 mm SL. In contrast, female 
C. gymnorhinus (Fig. 2B) lack cephalic spination, black 
pigmented blotches on dorsal and anal fins, and the 
dusky blind-side pigmentation characteristic of males. 
Also, with the onset of maturity, the ovaries undergo a 
conspicuous extensive posterior elongation (easily ob- 
served with light transmitted through the body), which, 
