The development of the spleen in the Australian lungfish, Neoceratodus forsteri Krefft, with special reference to its relationship to the “gastro”‐enteric vasculature

Abstract

The spleen of Neoceratodus forsteri Krefft grows in the shape of a " boomerang " on the left lateral-dorsal-right lateral part of the borderline between the foregut and the yolkgut . Development of the spleen follows the following stages: 1) appearance of the splenic primordium as a mesenchymal condensation in a limited portion of the region supplied by the third and fourth vitelline arteries on both sides, 2) development of the splenic sinuses within the primordium, 3) formation of the "gastric" and enteric splenic portal systems and 4) growth of the spleen along the anterior extremity of the spiral valve. The blood vascular dynamics of the foregut and the yolkgut are intimately involved with the formation of the spleen in this species. These processes were, therefore, compared with similar processes in other animals, and the characteristics of this organ common to vertebrates were investigated.

Vascular anatomy of the developing medaka, Oryzias latipes: A complementary fish model for cardiovascular research on vertebrates

“…Thus, the hepatic portal vein along the bile duct into the reticular hepatic sinusoid is formed (our unpublished results). This change in the hepatic portal system is equivalent to the change that has been shown to happen in other vertebrates and is also the essential process in the formation of the hepatic portal circulation in humans (Ura,1949; Yamada,1951; Aoyama,1956; Ishida,1956; Kawanishi,1956; Tada,1956; Miki,1968; Saito,1984).…”

“…Before the onset of blood circulation, the primary vascular system arises via vasculogenesis, which is characterized by in situ differentiation of selected mesodermal cells into endothelial cell precursors, or angioblasts. Classic morphogenetic studies have shown that the pattern of the circulatory system is species‐specifically characteristic and very constant in each species (Ura,1943,1949,1956; Aoyama,1956; Ishida,1956; Kawanishi,1956; Tada,1956; Miki,1968; Saito,1984). These studies also revealed that the common vascular pattern, which is composed of ventral aorta, aortic arches, dorsal aorta, transverse vessels (so‐called vitelline arteries), vitelline capillary plexus, and primary subintestinal vein (marginal vein), is highly conserved throughout the vertebrates (Fig.…”

“…Detailed embryonic studies on Amphioxus (Ura,1949), Lampetra (Yamada,1951), Trygon (Ura,1956), Neoceratodus (Saito,1984), Hynobious (Aoyama,1956), Caretta (Kawanishi,1956), Gallus (Ishida,1956), and Cricetus (Tada,1956) have revealed that the developmental process of the vascular system follows a reproducible stereotypic program in each species. From the comparative anatomical point of view, a common developmental pattern is highly conserved throughout the vertebrates during early development, although some species‐specific variations do exist.…”

The Vascular Anatomy of the Developing Zebrafish: An Atlas of Embryonic and Early Larval Development

“…Vessels in birds and mammals were historically thought to arise by growth into the embryo from extraembryonic tissues, a view refuted by many experimental studies (for example, Reagan, 1915;Sabin, 1917). Ura and colleagues published many detailed comparative studies on the development of the vascular system in a wide variety of species, including Amphiouxus (Ura, 1949), Lampetra (Yamada, 1951), Trygon (Ura, 1956), Neoceratodus (Saito, 1984), Hynobius (Aoyama, 1956), Caretta (Kawanishi, 1956), Gallus (Isida, 1956), and Cricetus (Tada, 1956), noting both similarities and some differences in the development of the embryonic vasculature of teleosts (see Discussion). More recent studies (e.g., Colle-Vandevelde, 1963;Isogai and Horiguchi, 1997;Iuchi and Yamamoto, 1983) have resolved at least some of the apparent differences and further supported the view that the earliest blood and blood vessels of developing teleosts are similar to those of other vertebrates in most respects.…”

Development of the vasculature of the pectoral fin in the Australian lungfish, Neoceratodus forsteri

“…The specimens were dissected under a binocular microscope and photographed. Arteries and veins were traced on the printed photographs at x90 magnification, while the specimens were being observed at the same magnification (Saito, 1984(Saito, , 1985. Two of the specimens are illustrated in Figure 1.…”