The pineal complex in the cichlid Cichlasoma dimerus: effect of different photoperiods on its cell morphology

AGUSTINA BIRBA; MARTÍN ROBERTO RAMALLO; LEONEL MORANDINI; MARÍA VIRGINIA VILLAFAÑE; CECILIA TUBERT; RENATA GUIMARÃES MOREIRA; MATÍAS PANDOLFI

JOURNAL OF FISH BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2014 vol. 85 p. 605 - 620

0022-1112

This research describes the pineal complex histology in juvenile and adult Cichlasoma dimerus, and the effect of different photoperiods on its cell morphology. In both juveniles and adults, the pineal complex of C. dimerus has three components: the pineal organ, consisting of a pineal vesicle (PV) and a pineal stalk, the parapineal organ and the dorsal sac. Although a strong morphological resemblance exists between the two stages, different synthesis patterns of cone and rod opsins were detected in the two life stages.An effect of the photoperiod lengthwas observed on putative pinealocytes? activity from the PV, measured indirectly through nuclear area morphometry. Individuals exposed to a natural photoperiod (14L:10D) had smaller nuclear areas (mean±s.e. = 13⋅82±1⋅52 μm2) than those exposed to a short photoperiod (8:16) (21⋅45±2⋅67 μm2; P