A light and electron microscopic study on the organization of the testis and the semicystic spermatogenesis of the genus Scorpaena (Teleostei,Scorpaenidae)

The testicular organization and semicystic spermatogenesis of Scorpaena porcus and Scorpaena scrofa are analyzed by means of optic and electron microscopy and immunohistochemical techniques. The testicular structure of S. porcus and S. scrofa belongs to the unrestricted spermatogonial type, but has typical features of the restricted type. Moreover, the structure presents an epithelioid arrangement of Sertoli and germ cells rather than the germinal epithelium that appears in the majority of teleosts. After the cysts open, Sertoli cells hypertrophy and remain on the basement membrane, linked by interdigitations and tight junctions and bordering the lumen of the lobule, which at this moment works as an efferent duct. Secretions of Sertoli cells usually function in the nutrition of germ cells, and they seem to contribute in it even in this kind of spermatogenesis in which the free lumen spermatids do not have any connection with Sertoli cells. In addition, Sertoli cells can divide after the cysts have broken apart and hypertrophied, suggesting that they are still important for the final maturation of spermatozoa and seminal fluid formation. J. Morphol. 2009. © 2009 Wiley‐Liss, Inc.     

Isolation and Amino Acid Sequences of Small Tryptic Peptides from the Oxidized Ala Chain of Ricin D

Twelve tryptic peptides as well as free arginine were isolated from the performic acid-oxidized Ala chain of ricin D by gel filtration on Sephadex G–25 and Dowex 1×2 column chromatography followed by paper chromatography. Total number of the amino acid residues in these peptides accounted for 90 out of 263 residues in the Ala chain of ricin D.

The amino acid sequences of nine peptides were determined by manual Edman degradation.     

The perinuclear space of pancreatic acinar cells and the synthetic pathway of zymogen in Scorpaena scrofa L.: ultrastructural aspects

Electron microscopic examination of exocrine pancreatic tissues from the fish Scorpaena scrofa L., probably captured while replenishing the acinar cells, shows two main functional cell morphologies of the same cell type. One cell functional aspect contains numerous well-contrasted small vesicles, the zymogenic vesicles. The other functional morphology is mainly represented by a few cells containing large apical zymogen vesicles with many empty RER cisterns. In our observations, the zymogenic vesicles are always studded with ribosomes. The main cytological finding is to report that zymogenic vesicles can be extruded from the perinuclear space and it confirms the suspected, synthetic activity of this cell compartment. The pool of zymogenic vesicles, maintaining their coat of ribosomes, then fuses and transfers their content into the cis Golgi complex network. Finally, the zymogen vesicles are produced following the classical secretory pathway from the trans Golgi saccular network into the supranuclear, apical region of the acinar cells where the largest vesicles concentrate their content until secretion.     

The pancreatic islets of the teleost Scorpaena scropha

Summary The principal pancreatic islets of the teleost Scorpaena scropha are found ultrastructurally to contain four different kinds of parenchymal cells, viz. ₁-(= D), ₂-, -and agranular cells. The -cells show considerable variations in the shape of the secretory granules. A peculiar feature is that many of these granules are composed of fibrillar subunits, often in parallel arrangement. All -granules are surrounded by membranes and between the membrane and the granule core there is a moderately wide electron lucent space. The electron density of the cytoplasm in the -cells varies somewhat. The ₂-cells possess typical secretory granules with an electron dense core and a closely applied membrane. The secretory granules in the ₁-cells show also a closely applied membrane but a less dense core. Also in the -cells the electron opacity of the cytoplasm varies. The agranular cells are mainly characterized by low cytoplasmic electron density, narrow cisterns of endoplasmic reticulum and sometimes a laminated Golgi complex. Small immature secretory granules are occasionally seen in the cytoplasm of these cells. The significance of the fibrillar -granules remains obscure.This work was supported by grants from the Nordic Insulin Fund, the Town of Umeå, the Swedish Medical Research Council (Project No. B69-12X-718-04A), and by a postdoctoral fellowship from the United States Public Health Service.     

A new species of the scorpionfish genus Scorpaena (Scorpaenidae) from Izu Peninsula, Pacific coast of Japan

A new species of scorpionfish, Scorpaena brevispina , is described on the basis of a single specimen collected from off the east coast of Izu Peninsula, Pacific coast of Japan, at a depth of 45 m. Scorpaena brevispina is distinguished from other Indo–Pacific species of Scorpaena by the following combination of characters: pectoral-fin rays 17; longitudinal scale rows 44; scales below lateral line 13; gill rakers 17; anterior surface of preocular spine with three vertical or slightly oblique ridges; lateral surface of maxilla without a distinct longitudinal ridge; lateral lacrimal spine present; extremely deep occipital pit; occipital pit rectangular in dorsal view, length distinctly less than width (length 53·3% of width); numerous small papillae on surface of occipital pit; pectoral fin relatively long (33·3% of standard length, L _S), posterior tip extending beyond verticals through last dorsal-fin spine base and second anal-fin spine base; relatively short third to fifth dorsal-fin spines (third spine length 14·6% of L _S, fourth spine 15·5%, and fifth spine 15·8%, respectively).     

The ovarian morphology of Scorpaena notata shows a specialized mode of oviparity

Scorpaena notata is an oviparous species with external fertilization that deposits its eggs in a gelatinous matrix. The internal epithelium of the ovarian wall is chiefly responsible for the production of this matrix, which is particularly abundant and viscous during the spawning period. The oocytes lack lipid droplets, so flotation and transport of the eggs is probably accomplished by means of the matrix that surrounds them. The ovarian stroma is situated along the centre of the gonad and the developing oocytes are connected to it by peduncles. The paucity and small size of the cortical alveoli of the oocytes are notable, as is the thinness of the zona radiata. These are characteristics that would be typical of viviparous species. The histological and ultrastructural observations lead to the conclusion that this species presents a type of oviparity more highly specialized than that of the majority of teleosts.