Histologija creva pastrmke (oncorhynchus mykiss) pre i posle obroka

Peharaste ćelije se nalaze u crevu riba, one sintetišu neutralne i sulfatne mucine i izlučuju sluz, podmazujući nesvareni materijal koji napreduje prema rektumu i štiteći sluzokožu digestivnog trakta. Promene u peharastim ćelijama creva riba posle obroka mogu pokazati odgovor na pojedinačni obrok obzirom na njihovu ulogu u procesu varenja. Cilj ovog istraživanja bio je procena promena histologije creva, pre hranjenja i 6h i 12 h posle obroka. Izgleda da 6h posle obroka kada je vrhunac sinteze proteina kod pastrmke, proces varenja je u toku, a peharaste ćelije izlučuju sluz pa se njihova veličina smanjuje. Slične dimenzije ovih ćelija pre obroka i 12 h posle ishrane potvrđuju da pastrmku treba hraniti 2 puta dnevno, a da drugo hranjenje treba obaviti 6 sati posle prvog. Ovo istraživanje daje više uvida u upravljanje ishranom u procesu uzgoja pastrmki

Histopathology of Aquatic Animals

Histopathology is the study of changes in any tissue associated with a disease or disorder. The word came from ancient Greek words: ´ιστóς (histos) = tissue, πα´θoς (pathos) = disease, and λoγι´α (logia) = word. It involves the examination of tissues and cells under a microscope in order to identify the alterations to the normal structure of tissues (and perhaps their etiology). Information obtained from the study of histopathological/histomorphological lesions in aquatic animals can be a useful addition when determining the general state of health of aquatic animals, especially if chronic stressors and/or pathogens are present. Compared to mammals, postmortem autolysis progresses very rapidly in most aquatic organisms. This fact makes histopathological examinations quite complex and demanding, not only in a histotechnical sense. A prerequisite for a successful study is the baseline knowledge of physiological processes and histological architecture of the studied species. The aim of this Special Issue was to contribute to the current state of knowledge on the histopathology of aquatic animals and to provide a collection of novel articles for biologists/veterinarians/animal scientists/other experts. The topic is extremely broad, and therefore, the published manuscripts are also diverse in terms of research areas, employed methodology and investigated species. Eight original studies and two review articles are part of this Special Issue and their short overview by two Guest Editors is given belo

Special Issue on the Histopathology of Aquatic Animals

Histopathology is the study of changes in any tissue associated with a disease or disorder [...

Fishmeal, plant protein, and fish oil substitution with single-cell ingredients in organic feeds for European sea bass (Dicentrarchus labrax)

publishedVersio

Bacterial biofilm development during experimental degradation of <em>Melicertus kerathurus</em> exoskeleton in seawater

Chitinolytic bacteria are widespread in marine and terrestrial environment, and this is rather a reflection of their principle growth substrate’s ubiquity, chitin, in our planet. In this paper, we investigated the development of naturally occurring bacterial biofilms on the exoskeleton of the shrimp Melicertus kerathurus during its degradation in sea water. During a 12-day experiment with exoskeleton fragments in batch cultures containing only sea water as the growth medium at 18 °C in darkness, we analysed the formation and succession of biofilms by scanning electron microscopy and 16S rRNA gene diversity by next generation sequencing. Bacteria belonging to the γ- and α-Proteobacteria and Bacteroidetes showed marked (less or more than 10%) changes in their relative abundance from the beginning of the experiment. These bacterial taxa related to known chitinolytic bacteria were the Pseudolateromonas porphyrae, Halomonas aquamarina, Reinekea aestuarii, Colwellia asteriadis and Vibrio crassostreae. These bacteria could be considered as appropriate candidates for the degradation of chitinous crustacean waste from the seafood industry as they dominated in the biofilms developed on the shrimp’s exoskeleton in natural sea water with no added substrates and the degradation of the shrimp exoskeleton was also evidenced

The remarkable vocal anatomy of the koala (Phascolarctos cinereus): insights into low-frequency sound production in a marsupial species

Koalas are characterised by a highly unusual vocal anatomy, with a descended larynx and velar vocal folds, allowing them to produce calls with disproportionately low frequencies. Here we use advanced imaging techniques, histological data, classical macroscopic dissection and behavioural observations to provide the first detailed description and interpretation of male and female koala vocal anatomy. We show that both males and females have an elongated pharynx and soft palate, resulting in a permanently descended larynx. In addition, the hyoid apparatus has a human-like configuration in which paired dorsal, resilient ligaments suspend the hyoid apparatus from the skull, while the ventral parts tightly connect to the descended larynx. We also show that koalas can retract the larynx down into the thoracic inlet, facilitated by a dramatic evolutionary transformation of the ventral neck muscles. First, the usual retractors of the larynx and the hyoid have their origins deep in the thorax. Second, three hyoid muscles have lost their connection to the hyoid skeleton. Third, the genioglossus and geniohyoid muscles have greatly increased in length. Finally, the digastric, omohyoid and sternohyoid muscles, connected by a common tendinous intersection, form a guiding channel for the dynamic down-and-up movements of the ventral hyoid parts and the larynx. We suggest that these features evolved to accommodate the low resting position of the larynx and assist in its retraction during call production. We also confirm that the edges of the intra-pharyngeal ostium have specialised to form the novel, extra-laryngeal velar vocal folds, which are much larger than the true, intra-laryngeal vocal folds in both sexes, but more developed and specialised for low frequency sound production in males than in females. Our findings illustrate that strong selection pressures on acoustic signalling not only lead to the specialisation of existing vocal organs, but can also result in the evolution of novel vocal structures in both sexes

Special Issue on the Histopathology of Aquatic Animals

[No abstract available