Secondary Vascular System on Michael’s Domain

Do fish have difficulty breathing?

Fri, 28 Jun 2024 00:00:00 +0000

Fish are breathing with their gills, but this is literally, for many of them, only half of the story. The difficulty of extracting oxygen from water is the single most defining force that shapes fish evolution. Land animals are mostly exposed to the same oxygen concentration, but fish need to operate in waters of vastly different and rapidly changing oxygen content. Moreover, water contains much less oxygen than air, and the diffusion of oxygen in water is magnitudes slower than the diffusion of oxygen in air. Therefore, fish evolution was forced to come up with creative ways to

Lymphatics as the origin of the fish secondary vascular system

Thu, 26 May 2022 00:00:00 +0000

In zebrafish, the blood vessels of the anal fin develop from lymphatics by transdifferentiation. Karina Yaniv presented unorthodox, but very compelling data supporting this conclusion last September at the Kloster Seeon Angiogenesis meeting .Now her paper has been published in Nature .

SVS or lymphatic system?

Sun, 26 Jan 2014 00:00:00 +0000

In 2003, I wrote a review article about the lymphatic system , in which I briefly discuss the general setup of the lymphatics in different animals and I got the part about the lymphatic system in fishes wrong. Or at the very least it was incomplete.While mammals, birds, reptiles and amphibia are quite easily defined animal classes, there is no animal class “fishes”. Different ways exist to classify “fishes”, but at least three animal classes are needed to accommodate the living “fishes”: cartilaginous fishes, ray-finned bony fishes and lobe-finned fishes. Almost all research on the lymphatic system of fishes had been done on teleost fishes (one of three infraclasses of the ray-finned bony fishes). Teleostei comprise most of the living fishes including the mostly studied zebrafish (Danio rerio) . So everything that follows is about this infraclass (and hence might not apply to sharks and sturgeons to name just two non-teleost fishes).