Apogon robbyi Gilbert and Tyler

Baldwin, Carole C., Brito, Balam J., Smith, David G., Weigt, Lee A. & Escobar-Briones, Elva, 2011, Identification of early life-history stages of Caribbean Apogon (Perciformes: Apogonidae) through DNA Barcoding, Zootaxa 3133, pp. 1-36 : 26

Apogon robbyi Gilbert and Tyler

Identification. One adult specimen ( Fig. 32 ), identified based on the presence of seven dusky stripes on the body ( Gilbert &Tyler, 1997; Gon 2002), served as the basis for genetic identification of two juveniles (Appendix 1).

Juveniles ( Fig. 33 ). The juveniles (17.0 and 22.0 mm SL) have the distinctive body stripes of adults, but the stripes are orange and paler than the dusky stripes in adults and not apparent in preserved specimens. There is yellow pigment on the first and second dorsal fins and upper lobe of the caudal fin that roughly mirrors that on the pelvic, anal, and lower lobe of the caudal fin, respectively. There is a round basicaudal spot of melanophores and orange chromatophores that persists in preserved specimens as a well-defined, medially situated, dark blotch. The larger juvenile has 12 gill rakers on the lower limb.

Comparisons Among Juveniles. Juvenile A. robbyi can be separated from other known Apogon juveniles by the seven orange-colored stripes on body. It resembles young A. quadrisquamatus and A. mosavi in having chromatophores on the vertical and pelvic fins, but in A. robbyi this pigment is yellow vs. yellow and orange or all orange. As in A. quadrisquamatus and A. mosavi , the pigment on the dorsal fins and upper caudal lobe appears to mirror that on the pelvic and anal fins and lower lobe of the caudal fin. Modal numbers of gill rakers on the lower limb of the first arch are useful in separating juvenile A. robbyi (12–13) from A. mosavi (14–15) but not from A. quadrisquamatus and Apogon sp. 2 (13).

Figures

FIGURE 32. Apogon robbyi, adult, 27.0 mm SL, DNA # BLZ 6179, photograph by J. Mounts and C. Baldwin.

FIGURE 33. Apogon robbyi, juvenile, 22.0 mm SL, DNA # BLZ 6083, photograph by C. Baldwin and L. Weigt.