Structure of the reproductive system and hectocotylus in males of lesser flying squid Todaropsis eblanae (Cephalopoda: Ommastrephidae)

This paper introduces new data on Todaropsis eblanae morphology, morphometry and functional aspects of the male reproductive system and hectocotylus. Spermatophores differ in specimens from the Atlantic Ocean (average length, 18.28 ± 1.45 mm, 15.63 ± 0.8% of mantle length; weight, 2.0–12.0 mg) and the Indian Ocean (average length, 24.8 ± 2.85 mm, 16.9 ± 2.1% of mantle length; weight, 35.0–39.6 mg) (t?=?3.14; p < 0.01 for absolute sizes and t?=?0.711; p > 001 for relative sizes). An additional important distinctive trait is the form of connection of the cement body with the ejaculatory tube. In recent years, T. eblanae has been regularly caught in the Barents Sea, meaning its range has extended to subarctic waters. The morphology and morphometry of the spermatophoric complex of organs did not vary in investigated parts of its range. Hectocotylus patterns and some important spermatophore traits distinguish Todaropsis from other Ommastrephidae.     

A redescription of the fossil coleoid cephalopod genus Palaeololigo Naef, 1921 (Decapodiformes: Palaeololiginidae) and its relationship to Recent squids

Neocoleoid cephalopods are poorly represented in the fossil record and fossils which can be confidently aligned with extant species are very scarce. The rare Solnhofen genus Palaeololigo is an exception to this, showing marked resemblance to Recent squids. Naef misinterpreted the structure of the fossilized gladius of Palaeololigo and the present study redescribes the genus. The gladius and fossilized fin impressions of Palaeololigo closely resemble that of the extant decapodiform squid genera Bathyteuthis and Chtenopteryx (Superfamily Bathyteuthoidea). The possible relationship between Palaeololigo and the bathyteuthoids and their position in decapodiform phylogenetics is discussed.     

Immunocytochemical reaction of a haemocyanin antibody in the midgut gland ofNautilus (Cephalopoda,Tetrabranchiata)

The branchial gland of the dibranchiate cephalopods is described as the site of haemocyanin synthesis. Because there is no equivalent to this organ in tetrabranchiate cephalopods the localization of haemocyanin synthesis remained unknown for a long time. In this study we could confirm the conclusions from prelimnary investigations concerning the copper content of the midgut gland ofNautilus, which gave the first indications for a possible localization of haemocyanin synthesis in this organ. We developed a polyclonal antibody againstNautilus haemocyanin, tested its specificity, and used it on ultra-thin sections of the tissue of the midgut gland. It could be shown that there is a clear imunogold precipitation only on the triangular basal cells in the terminal alveoli. All the other types of cell in this organ were free of any immunoreactivity. It can be supposed that the triangular basal cells in the terminal alveoli of the midgut gland are the sites of haemocyanin synthesis inNautilus.