02505naa a2200325 a 450000100080000000500110000800800410001902400520006010000180011224501290013026000090025952015170026865000330178565300200181865300180183865300410185665300100189765300180190770000190192570000210194470000180196570000230198370000230200670000250202970000190205470000250207370000160209870000170211477300480213121756972025-05-26       2025    bl uuuu     u00u1 u    #d7 ahttps://doi.org/10.1007/s10641-025-01668-w2DOI1 aXAVIER, L. G.  aNew occurrence record and dermal denticles of megamouth sharks from the Southwest Atlantic Coast.h[electronic resource]  c2025  aThe megamouth shark, Megachasma pelagios, is a rare circumtropical species with a dis- tinctive appearance. To date, only 273 confirmed occurrence records have been documented globally. This study reports the third occurrence of a mega- mouth shark on the Brazilian coast and provides descriptions of the dermal denticles of all three specimens recorded in the country. On September 10, 2018, a megamouth shark was found floating off Pedra do Sal Beach, Parnaíba, Piauí, Northeastern, Brazil. A mitochondrial ND2 sequence was obtained from this specimen, confirming its identity. Skin sam - ples from this specimen, as well as from the two other previously recorded individuals from Southeastern Brazil (an adult stranded in Arraial do Cabo, Rio de Janeiro, and a juvenile captured off the coast of São Paulo), were analyzed to describe the dermal denti- cles using scanning electron microscopy and ster- eomicroscopy. The dermal denticles from the Brazil- ian specimens exhibited distinct shapes depending on body region. The specimen from São Paulo showed differences in the dermal denticles to those of adults, with an increase in the ridges and a reduction of cusps, particularly in the caudal peduncle, cheek, and pelvic fin regions. Furthermore, the dermal denticles of the two juvenile megamouth sharks exhibit, in gen- eral, a distinct arrangement pattern, appearing more closely spaced and slightly imbricated  when com- pared to the adult from Arraial do Cabo and those reported in the literature.  aScanning electron microscopy  aEscala placoide  aMegachasmidae  aMicroscopia eletrônica de varredura  aMtDNA  aPlacoid scale1 aLIMA, A. K. L.1 aMIGUEL, E. DE C.1 aSICILIANO, S.1 aHAUSER‑DAVIS, R.1 aBORDALLO, P. do N.1 aARAGÃO, G. M. DE O.1 aSOTO, J. M. R.1 aFREITAS, J. E. P. DE1 aCHARVET, P.1 aFARIA, V. V.  tEnvironmental Biology of Fishes, Jan, 2025.