scholarly journals Calanoid copepods feed and produce eggs in the presence of toxic cyanobacteria Nodularia spumigena

2002 ◽  
Vol 47 (3) ◽  
pp. 878-885 ◽  
Author(s):  
Marja Koski ◽  
Katrin Schmidt ◽  
Jonna Engström-Öst ◽  
Markku Viitasalo ◽  
Sigrún Jónasdóttir ◽  
...  
Keyword(s):  
Calanoid Copepods ◽  
Nodularia Spumigena ◽  
Toxic Cyanobacteria

scholarly journals Effects of toxic cyanobacteria on a plankton assemblage: community development during decay of Nodularia spumigena

2002 ◽  
Vol 232 ◽  
pp. 1-14 ◽  
Author(s):  
J Engström-Öst ◽  
M Koski ◽  
K Schmidt ◽  
M Viitasalo ◽  
SH Jónasdóttir ◽  
...  
Keyword(s):  
Community Development ◽  
Nodularia Spumigena ◽  
Toxic Cyanobacteria

Toxic blooms of cyanobacteria in Lake Alexandrina, South Australia — Learning from history

1994 ◽  
Vol 45 (5) ◽  
pp. 731 ◽  
Author(s):  
GA Codd ◽  
DA Steffensen ◽  
MD Burch ◽  
PD Baker
Keyword(s):  
South Australia ◽  
Cyanobacterial Blooms ◽  
Nodularia Spumigena ◽  
Toxic Cyanobacteria ◽  
Toxic Blooms ◽  
Learning From History

Early accounts by European explorers and settlers of South Australia contain numerous references to scums or discoloured water that are consistent with cyanobacterial blooms. Documented reports refer back to at least 1853. The first detailed scientific account of toxic cyanobacteria appeared in 1878. In a perceptive and prescient paper in Nature, the Adelaide assayer and chemist George Francis reported on stock deaths at Milang on the shores of Lake Alexandrina in South Australia. Francis attributed the deaths to the ingestion and toxicity of scums of the cyanobacterium Nodularia spumigena. Reports of cyanobacterial blooms, scums and associated problems in Lake Alexandrina and in the River Murray between about 1851 and 1888 are discussed and comparisons are made with the reactions to blooms a century later.

Consumption of cyanobacteria by freshwater zooplankton: Implications for the success of 'top-down' control of cyanobacterial blooms in Australia

1994 ◽  
Vol 45 (5) ◽  
pp. 875 ◽  
Author(s):  
PI Boon ◽  
SE Bunn ◽  
JD Green ◽  
RJ Shiel
Keyword(s):  
Northern Hemisphere ◽  
Algal Blooms ◽  
Trophic Structure ◽  
Cyanobacterial Blooms ◽  
Inland Waters ◽  
Calanoid Copepods ◽  
Top Down ◽  
Fresh Waters ◽  
Toxic Cyanobacteria ◽  
The Common

Two main approaches have been mooted for the management of fresh waters to prevent or control cyanobacterial blooms: a 'bottom-up' approach in which the supply of essential nutrients is restricted, and a 'top-down' or 'biomanipulation' approach in which attempts are made to restructure the food web to maximize consumption of noxious cyanobacteria by herbivorous zooplankton. In this review, the published literature is examined to gauge whether the common zooplankton of Australian fresh waters have the capacity to control cyanobacterial blooms, especially of toxic forms, and thus whether the biomanipulation approach might be applied successfully in Australia. As zooplankton assemblages in Australian inland waters are quite different in composition from those of the Northern Hemisphere, they are unlikely to respond to manipulations of trophic structure in a similar way. The most common zooplankters in Australian inland waters, calanoid copepods and rotifers, have less potential for controlling cyanobacterial blooms than do large cladocerans. The latter are common in the Northern Hemisphere and are considered requisite for the control of cyanobacterial blooms. Toxic cyanobacteria, which cause the most severe environmental problems, have well documented detrimental effects on zooplankton. The few reports of zooplankton grazing on cyanobacteria in Australian fresh waters do not indicate that native zooplankton can consume noxious cyanobacteria at the rates required for control of algal blooms. There may, therefore, be grounds for strong reservations about the likely success of programmes proposed to control cyanobacterial blooms by the manipulation of trophic structure in Australian fresh waters.

Ultrastructural identification of three types of sensory setae on copepod antennae

1995 ◽  
Vol 53 ◽  
pp. 956-957
Author(s):  
T. M. Weatherby ◽  
P.H. Lenz
Keyword(s):  
Phase Locking ◽  
Membrane Surface ◽  
Reaction Times ◽  
High Sensitivity ◽  
Structural Features ◽  
Calanoid Copepods ◽  
Marine Food Webs ◽  
Dendritic Membrane ◽  
Ultrastructural Characterization

Crustaceans, as well as other arthropods, are covered with sensory setae and hairs, including mechanoand chemosensory sensillae with a ciliary origin. Calanoid copepods are small planktonic crustaceans forming a major link in marine food webs. In conjunction with behavioral and physiological studies of the antennae of calanoids, we undertook the ultrastructural characterization of sensory setae on the antennae of Pleuromamma xiphias.Distal mechanoreceptive setae exhibit exceptional behavioral and physiological performance characteristics: high sensitivity (<10 nm displacements), fast reaction times (<1 msec latency) and phase locking to high frequencies (1-2 kHz). Unusual structural features of the mechanoreceptors are likely to be related to their physiological sensitivity. These features include a large number (up to 3000) of microtubules in each sensory cell dendrite, arising from or anchored to electron dense rods associated with the ciliary basal body microtubule doublets. The microtubules are arranged in a regular array, with bridges between and within rows. These bundles of microtubules extend far into each mechanoreceptive seta and terminate in a staggered fashion along the dendritic membrane, contacting a large membrane surface area and providing a large potential site of mechanotransduction.

Seasonal diving and foraging behaviour of Eastern Canada-West Greenland bowhead whales

2020 ◽  
Vol 643 ◽  
pp. 197-217 ◽  
Author(s):  
SME Fortune ◽  
SH Ferguson ◽  
AW Trites ◽  
B LeBlanc ◽  
V LeMay ◽  
...  
Keyword(s):  
Climate Change ◽  
Late Summer ◽  
Calanoid Copepods ◽  
Eastern Canada ◽  
West Greenland ◽  
Bowhead Whales ◽  
Seasonal Movement ◽  
Dive Behaviour ◽  
Calanus Glacialis ◽  
Canada West

Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.

Sign in / Sign up

Export Citation Format

Share Document