Sideway swimming behaviour by aggregating blacktip sharks (Carcharhinus limbatus) in mid-water column

2021 ◽  
Vol 51 (6) ◽  
Author(s):  
Ornella C. Weideli ◽  
Hannah Medd
Keyword(s):  
Water Column ◽  
Swimming Behaviour ◽  
Carcharhinus Limbatus

Sexually Dimorphic Free-Swimming Behaviour in the Amphipod Crustacean Ampelisca Abdita

1991 ◽  
Vol 71 (3) ◽  
pp. 655-663 ◽  
Author(s):  
B. Borowsky ◽  
P. Aitken
Keyword(s):  
Water Column ◽  
Swimming Behaviour ◽  
Sexually Dimorphic ◽  
Free Swimming ◽  
Amphipod Crustacean ◽  
Males And Females

This paper describes a novel sexually dimorphic pattern of behaviour in the tube-building amphiplodAmpelisca abdita (Mills). Mature males and females enter the water column at night. However, while males enter the water column every night, females enter it only when they moult. Since female amphipods only mate shortly after they moult, it is hypothesized that this sexually dimorphic pattern of free-swimming behaviour is an adaptation that permits males and receptive females to locale each other during the brief period when copulation can occur, while reducing the time that females are exposed to pelagic predators.

scholarly journals In situ swimming speed and swimming behaviour of fish feeding on the krill Meganyctiphanes norvegica

2005 ◽  
Vol 62 (8) ◽  
pp. 1822-1832 ◽  
Author(s):  
M SR Onsrud ◽  
S Kaartvedt ◽  
M T Breien
Keyword(s):  
Target Tracking ◽  
Water Column ◽  
Swimming Speed ◽  
Original Data ◽  
Clupea Harengus ◽  
Swimming Behaviour ◽  
Fish Feeding ◽  
Sea Bottom ◽  
Acoustic Target

In situ swimming speed and swimming behaviour of dielly migrating planktivorous fish were studied at a 120-m-deep location. Acoustic target tracking was performed using a hull-mounted transducer and submersible transducers located on the sea bottom and free hanging in the water column. The original data displayed a relationship between distance to transducer and swimming speed. A simplistic smoother applied during post-processing, appeared to break this relationship. Target tracking thus provided robust results on in situ swimming behaviour throughout the water column. Swimming speeds of deep-living fish, mainly Norway pout (Trisopterus esmarkii) and whiting (Merlangius merlangus), were highest during the day (speeds centred around 14–16 cm·s–1) and decreased somewhat by night (modes around 10–11 cm·s–1). Fish in the upper 10–30 m swam somewhat faster (speeds ranging from 16 to 24 cm·s–1). Fish in the upper layer at night were mainly Atlantic herring (Clupea harengus), sprat (Sprattus sprattus), and whiting. We ascribe the reduction of swimming speed in deep-living fish at night to a switch from visual feeding during daytime to nonvisual feeding by night. We suggest that shallow-living fish could forage visually even by night. Most tracks were fairly short, but some long tracks unveiled elaborate swimming paths as well as cyclic swimming behaviour.

scholarly journals Muscular adaptations in swimming scale worms (Polynoidae, Annelida)

2021 ◽  
Vol 8 (10) ◽  
Author(s):  
Marc C. Allentoft-Larsen ◽  
Brett C. Gonzalez ◽  
Joost Daniels ◽  
Kakani Katija ◽  
Karen Osborn ◽  
...  
Keyword(s):  
Water Column ◽  
Deep Sea ◽  
Three Dimensional ◽  
Swimming Behaviour ◽  
Shallow Waters ◽  
Video Recordings ◽  
Structural Loss ◽  
Muscular Adaptations ◽  
Over Time

Annelids are predominantly found along with the seafloor, but over time have colonized a vast diversity of habitats, such as the water column, where different modes of locomotion are necessary. Yet, little is known about their potential muscular adaptation to the continuous swimming behaviour required in the water column. The musculature and motility were examined for five scale worm species of Polynoidae (Aphroditiformia, Annelida) found in shallow waters, deep sea or caves and which exhibit crawling, occasional swimming or continuous swimming, respectively. Their parapodial musculature was reconstructed using microCT and computational three-dimensional analyses, and the muscular functions were interpreted from video recordings of their locomotion. Since most benthic scale worms are able to swim for short distances using body and parapodial muscle movements, suitable musculature for swimming is already present. Our results indicate that rather than rearrangements or addition of muscles, a shift to a pelagic lifestyle is mainly accompanied by structural loss of muscle bundles and density, as well as elongation of extrinsic dorsal and ventral parapodial muscles. Our study documents clear differences in locomotion and musculature among closely related annelids with different lifestyles as well as points to myoanatomical adaptations for accessing the water column.

A temporarily planktonic terebellid polychaete

2003 ◽  
Vol 83 (4) ◽  
pp. 771-774 ◽  
Author(s):  
Wilfried Westheide
Keyword(s):  
Water Column ◽  
West Coast ◽  
Free Water ◽  
Swimming Behaviour ◽  
Environmental Disturbance ◽  
The South ◽  
South West ◽  
South West Coast ◽  
Flight Reaction

Mass swarming of a basically sessile terebellid polychaete was observed in the free water column off the south-west coast of Madagascar. Specimens are described and tentatively identified as Loimiamedusa (Savigny, 1818). Swimming behaviour is documented and the phenomenon is discussed as a flight reaction to an environmental disturbance event.

Comparison of the performance of oscillating water column devices based on arrangements of water columns

2020 ◽  
Vol 14 (3) ◽  
pp. 7082-7093
Author(s):  
Jahirwan Ut Jasron ◽  
Sudjito Soeparmani ◽  
Lilis Yuliati ◽  
Djarot B. Darmadi
Keyword(s):  
Wave Propagation ◽  
Water Column ◽  
Water Depth ◽  
Graphical Form ◽  
Wave Power ◽  
Oscillating Water Column ◽  
Power Absorption ◽  
Water Columns ◽  
Single Column ◽  
Parallel Arrangement

The hydrodynamic performance of oscillating water column (OWC) depends on the depth of the water, the size of the water column and its arrangement, which affects the oscillation of the water surface in the column. An experimental method was conducted by testing 4 water depths with wave periods of 1-3 s. All data recorded by the sensor is then processed and presented in graphical form. The research focused on analyzing the difference in wave power absorption capabilities of the three geometric types of OWC based on arrangements of water columns. The OWC devices designed as single water column, the double water column in a series arrangement which was perpendicular to the direction of wave propagation, and double water column in which the arrangement of columns was parallel to the direction of wave propagation. This paper discussed several factors affecting the amount of power absorbed by the device. The factors are the ratio of water depth in its relation to wavelength (kh) and the inlet openings ratio (c/h) of the devices. The test results show that if the water depth increases in the range of kh 0.7 to 0.9, then the performance of the double chamber oscillating water column (DCOWC) device is better than the single chamber oscillating water column (SCOWC) device with maximum efficiency for the parallel arrangement 22,4%, series arrangement 20.8% and single column 20.7%. However, when referring to c/h, the maximum energy absorption efficiency for a single column is 27.7%, double column series arrangement is 23.2%, and double column parallel arrangement is 29.5%. Based on the results of the analysis, DCOWC devices in parallel arrangement showed the ability to absorb better wave power in a broader range of wave frequencies. The best wave of power absorption in the three testing models occurred in the wave period T = 1.3 seconds.

Control of heat transfer in a geysering water column by ultrasound emission

2002 ◽  
Author(s):  
Hideo Kimoto ◽  
Takashi Fujii ◽  
Kenta Fujiwara
Keyword(s):  
Heat Transfer ◽  
Water Column
Sign in / Sign up

Export Citation Format

Share Document