Voliani a (2 Ergebnisse)

The presence of undigested remains, particularly chitinous beaks, in the stomachs of teuthophagous organisms provides crucial insight into cephalopod consumption. This manual serves as a guide for 42 species identification of cephalopod in the Mediterranean Sea using their beaks and supports research on predator-prey interactions, predator ecology, and the distribution and abundance of lesser-known cephalopod species. The guide is structured in three parts. The first introduces the general anatomy and physiology of the buccal bulb and the morphology of upper and lower beaks. A glossary is included to clarify morphological terminology used throughout the manual. An updated systematic list of the Mediterranean cephalopod species under study in this paper, nomenclaturally based on WoRMS, is included. The second and third parts are composed of identification sheets dedicated to individual species, focusing on lower and upper beaks, respectively. Each sheet highlights the key morphological features necessary for accurate identification. A consistent approach is used for both beak types, structured around three levels of diagnostic features: General Characteristics (differentiating Decapodiformes and Octopodiformes), Primary Identifying Characteristics (for initial morphological filtering), and Specific Identifying Characteristics (for definitive species-level identification). Beaks are photographed in three standard views ? lateral, oblique, and dorsal ? with frontal views included when informative. The cephalopod specimens from which beaks were extracted were collected in stages, based on sampling opportunities, from the Ligurian and northern-central Tyrrhenian Seas (FAO GSA 9). An essential component of the study was the collection of beaks from the stomachs of teuthophagous predators. This enabled the examination of tens of thousands of beaks, refining the descriptions and correlating cephalopod species with their predators. Mantle length-to-beak size and weight-to-beak size relationships available in the literature were tested for their effectiveness in estimating specimen size and weight. Finally, the manual aims to establish an ecological connection between cephalopod species and their habitual predators, creating a kind of ?who eats whom? in order to initially guide and direct the recognition of beaks in gastric contents. For this purpose, tables have been prepared, summarizing the results obtained from the analyses of gastric contents from the main species of teuthophagous cetaceans and fish, particularly focusing on the Mediterranean Sea. 133 pp., 269 figs, 19 tabs, br. 4.…