Effect of live-storage period and temperature on oxygen consumption rate in the cold-water sea cucumber Parastichopus tremulus

Sea cucumbers are of great significance in marine ecosystems all over the world. The red sea cucumber Parastichopus tremulus is also considered commercially interesting but very little information is available on its ecology and physiology. This study aimed at investigating this North Atlantic species` oxygen demand in relation to live-storage period and temperature in an attempt to deliver some physiological puzzle pieces useful in a potential aquacultural context. Oxygen consumption rate (OCR) was measured in P. tremulus stored in a flow-through system for up to one year, and in recirculation systems at different temperatures (4, 8 and 12°C) for up to four weeks. Throughout the experimental period, biometric data were collected from the different treatment groups and a condition index (CI) calculated. The results showed that long-term storage affected OCR and CI, which increased and decreased with time, respectively. Storage at 4°C resulted in significantly lower OCR and higher CI compared to 8 and 12°C after four weeks, suggesting that 4°C may be best for maintaining body mass during short-term storage, whereas storage at 8 and 12°C may require supplementary feeding to avoid biomass loss. Data presented in this study may be useful for a range of applications, for example in a prospective aquaculture setting, for optimizing live seafood storage, but also for impact assessment and management of wild stocks

Seleksjon i reketrål: overlevelse til reker som selekteres ut i overflaten - Sluttrapport for FHF-prosjekt 901661

Fra 2020 til 2022 ble det gjennomført en rekke forsøk i Skagerrak i forbindelse med seleksjon og overlevelse til dypvannsreker (Pandalus borealis). Hovedmålsettingen var å kvantifisere hvor stor andel av trålsekkseleksjonen av reker som skjer i havoverflaten og undersøke overlevelsen til rekene som selekteres ut her. Overlevelsen til reker som unnslipper i overflaten avhenger av miljøforholdene i overflaten og hvor lenge de eksponeres for disse. Høy dødelighet på utsortert småreke vil være en alvorlig feilkilde i bestandsberegninger og også reduserer utbyttet fra bestanden. Forsøkene ble inndelt i fire arbeidspakker: Kvantifisering av seleksjon i havoverflate og på bunn, adferds- og toleranseundersøkelser, metodeutvikling for overlevelsesforsøk i felt og overlevelsesforsøk i rekefiske (feltforsøk).Seleksjon i reketrål: overlevelse til reker som selekteres ut i overflaten - Sluttrapport for FHF-prosjekt 901661publishedVersio

Apathy is associated with executive functioning in first episode psychosis

<p>Abstract</p> <p>Background</p> <p>The underlying nature of negative symptoms in psychosis is poorly understood. Investigation of the relationship between the different negative subsymptoms and neurocognition is one approach to understand more of the underlying nature. Apathy, one of the subsymptoms, is also a common symptom in other brain disorders. Its association with neurocognition, in particular executive functioning, is well documented in other brain disorders, but only studied in one former study of chronic patients with schizophrenia. This study investigates the association between apathy and neurocognitive functioning in patients with first episode psychosis (FEP), with the hypothesis that apathy is more associated with tests representing executive function than tests representing other neurocognitive domains.</p> <p>Methods</p> <p>Seventy-one FEP patients were assessed with an extensive neuropsychological test battery. Level of apathy was assessed with the abridged Apathy Evaluation Scale (AES-C-Apathy).</p> <p>Results</p> <p>AES-C-Apathy was only significantly associated with tests from the executive domain [Semantic fluency (r = .37, p < .01), Phonetic fluency (r = .25, p < .05)] and working memory [Letter Number Span (r = .26; p =< .05)]; the first two representing the initiation part of executive function. Confounding variables such as co-occuring depression, positive symptoms or use of antipsychotic medication did not significantly influence the results.</p> <p>Conclusion</p> <p>We replicated in FEP patients the relationship between apathy and executive functioning reported in another study for chronic patients with schizophrenia. We also found apathy in FEP to have the same relationship to executive functioning, as assessed with the Verbal fluency tests, as that reported in patients with other brain disorders, pointing to a common underlying nature of this symptom across disorders.</p

Acidification and warming affect both a calcifying predator and prey, but not their interaction

Both ocean warming and acidification have been demonstrated to affect the growth, performance and reproductive success of calcifying invertebrates. However, relatively little is known regarding how such environmental change may affect interspecific interactions. We separately treated green crabs Carcinus maenas and periwinkles Littorina littorea under conditions that mimicked either ambient conditions (control) or warming and acidification, both separately and in combination, for 5 mo. After 5 mo, the predators, prey and predator-prey interactions were screened for changes in response to environmental change. Acidification negatively affected the closer-muscle length of the crusher chela and correspondingly the claw-strength increment in C. maenas. The effects of warming and/or acidification on L. littorea were less consistent but indicated weaker shells in response to acidification. On the community level, however, we found no evidence that predator-prey interactions will change in the future. Further experiments exploring the impacts of warming and acidification on key ecological interactions are needed instead of basing predictions of ecosystem change solely on species-specific responses to environmental change