for comparison of the food value of four different epecies of aquatic weeds: potamogeton pectinatus , potamogeton lucens, potamogeton perfoliatus, najas minor and two species of terrestrial grass: medicago sativa and cynodon dactylon by grass carp (ctenopharyngodon ideda), was studied in the shahicl rejai fishfarm in sari (province of mazandaran). totally 6 concrete ponds with 30 cubic meter vo...

In August 1985 and 1986, a senes of bathyphotometric measurements were made In icefree waters of Vestfjord, Norway, to quantify stimulable in situ bioluminescence. In 1986, we tested and identified the causative bioluminescent plankton. In all profiles, peak or maximum bioluminescence intensity was always within a zone of 15 to 30m below sea surface, with marked decreases below 50m. Maximum bio...

To learn how organisms apportion space in the open ocean, biological oceanographers have sought to improve temporal and spatial resolution of ocean sampling systems. Their objectives are to simultaneously measure physical, chemical and biological structure in the water column in order to ®nd signi®cant correlations that may reveal underlying processes. Here we report one such correlation betwee...

Abstract Species distribution models for marine organisms are increasingly used a range of applications, including spatial planning, conservation, and fisheries management. These have been constructed using variety mathematical forms drawing on both physical biological independent variables; however, what might be called first‐generation mainly followed the form linear models, or smoothing spli...

Abstract Diel vertical migration (DVM) of krill was studied throughout 36 h at a fixed station (46.05°S, 66.19°W; 98-m depth) located in the center San Jorge Gulf, Southern Patagonia area, during February 2014. Using an echosounder system, combined with autonomous Video Plankton Recorder (Auto-VPR) and Jacknet samplings, we describe pattern, associated biomass macrozooplankton species involved....