thatfishkid:todropscience:SCIENTISTS CONFIRM THE PRESENCE OF LUNGS IN COELACANTHSCoelacanths are lob
thatfishkid:todropscience:SCIENTISTS CONFIRM THE PRESENCE OF LUNGS IN COELACANTHSCoelacanths are lobe-finned fishes, that look somewhat like limbs. Known from the Devonian to Recent that were long considered extinct, until the discovery of two living species in deep marine waters of the Mozambique Channel and Sulawesi. Despite extensive studies, the pulmonary system of extant coelacanths has not been fully investigated.Since its rediscovery in 1938, scientists doubted the existence of a lung in the living species West Indian Ocean coelacanth (Latimeria chalumnae) when compared with fossil species. Now, an international team of researchers confirm the presence of functional lungs at early embryonic stages; these lungs lose function and become vestigial lungs in adulthood. The finding sheds light on how ancient relatives may have lived about 410 million years ago.Coelcanths is a heavily built fish living in rocky environments between 110 and 400 m deep in the coastal waters of the Mozambique Channel and of Sulawesi. This large animal (up to 2 m long) is ovoviviparous. The young develop in the oviduct of the female, which can give birth to 26 live pups of about 35 cm long. Juvenile coelacanths (below 80 cm long) are rarely observed or caught. The presence of a large calcified sheath in the abdominal cavity of fossil coelacanths has been known since the 19th century but was previously regarded as either an ‘internal osseous viscus’ (unknown internal organ), a bladder or swimbladder. Only recently this organ has been formally described in fossils coelacanths as a pulmonary organ composed of large and rounded calcified plates, positioned ventrally relative to the gut, and with a single anterior opening under the opercle. The parallel development of a fatty organ for buoyancy control suggests a unique adaptation to deep water. Three-dimensional reconstructions of the pulmonary complex of West Indian Ocean coelacanth (L. chalumnae) at different ontogenetic stages.Photograph by Peter ScoonesReference (open access) Cupello et al. 2015. Allometric growth in the extant coelacanth lung during ontogenetic development. Nature CommunicationsThe worlds coolest fish right here -- source link