Toxicity of Twenty-Three Insecticides to a Tubificid Worm Branchiura sowerbyi from the Mississippi Delta1

1973 ◽  
Vol 66 (1) ◽  
pp. 70-74 ◽  
Author(s):  
S. M. Z. Naqvi
1988 ◽  
Vol 137 (1) ◽  
pp. 487-500 ◽  
Author(s):  
Mark J. Zoran ◽  
Charles D. Drewes

The rapid tail withdrawal of the tubificid worm, Branchiura sowerbyi, was studied using correlated electrophysiological and behavioural analyses. The minimal response latency (i.e. time from onset of mechanical stimulus to onset of withdrawal) was approximately 7 ms, faster than the escape responses of any previously studied invertebrate. Factors contributing to the speed and efficacy of this response include: (1) a sensitive mechanosensory system for detecting potential prey, (2) a short latency for excitation along afferent and efferent pathways, (3) a rapid intersegmental conduction of lateral giant fibre spikes, (4) a short coupling time from muscle excitation to the onset of shortening, and (5) the requirement of only a single lateral giant fibre spike for a complete (all-or-none) response. Videotaped sequences of predator—prey interactions showed that such reflex speed permits effective escape from the strike of the bluegill (Lepomis macrochirus).


2007 ◽  
Vol 384 (1-3) ◽  
pp. 252-263 ◽  
Author(s):  
Virginie Ducrot ◽  
Alexandre R.R. Péry ◽  
Hervé Quéau ◽  
Raphaël Mons ◽  
Michel Lafont ◽  
...  

2004 ◽  
Vol 23 (1) ◽  
pp. 55-63 ◽  
Author(s):  
A. Kaviraj ◽  
F. Bhunia ◽  
N. C. Saha

Static renewal bioassays were conducted in the laboratory and in outdoor artificial enclosures to evaluate toxic effects of methanol to one teleost fish and two aquatic invertebrates and to limnological variables of aquatic ecosystem. Ninety-six-hour acute toxicity tests revealed cladoceran crustacea Moina micrura as the most sensitive to methanol (LC50, 4.82 g/L), followed by freshwater teleost Oreochromis mossambicus (LC50, 15.32 g/L) and oligochaete worm Branchiura sowerbyi (LC50, 54.89 g/L). The fish, when exposed to lethal concentrations of methanol, showed difficulties in respiration and swimming. The oligochaete body wrinkled and fragmented under lethal exposure of methanol. Effects of five sublethal concentrations of methanol (0, 23.75, 47.49, 736.10, and 1527.60 mg/L) on the feeding rate of the fish and on its growth and reproduction were evaluated by separate bioassays. Ninety-six-hour bioassays in the laboratory showed significant reduction in the appetite of fish when exposed to 736.10 mg/L or higher concentrations of methanol. Chronic toxicity bioassays (90 days) in outdoor enclosures showed a reduction in growth, maturity index and fecundity of fish at 47.49 mg/L or higher concentrations of methanol. Primary productivity, phytoplankton population, and alkalinity of water were also reduced at these concentrations. Chronic exposure to 1527.60 mg/L methanol resulted in damages of the epithelium of primary and secondary gill lamellae of the fish. The results revealed 23.75 mg/L as the no-observed-effect concentration (NOEC) of methanol to freshwater aquatic ecosystem.


Oikos ◽  
1980 ◽  
Vol 34 (1) ◽  
pp. 88 ◽  
Author(s):  
H. Fukuhara ◽  
E. Kikuchi ◽  
Y. Kurihara

2013 ◽  
Vol 112 (4) ◽  
pp. 1575-1582 ◽  
Author(s):  
Bing-Wen Xi ◽  
Jin-Yong Zhang ◽  
Jun Xie ◽  
Liang-Kun Pan ◽  
Pao Xu ◽  
...  
Keyword(s):  

1981 ◽  
Vol 59 (6) ◽  
pp. 939-965 ◽  
Author(s):  
H. R. Baker ◽  
R. O. Brinkhurst

The genus Monopylephorus Levinsen, 1884 is revised, and divided into three genera. Monopylephorus includes rubroniveus, limosus, kermadecensis, parvus, irroratus, aucklandicus, and the new species cuticulatus and evertus. Rhizodrilus Smith, 1900 includes lacteus, africanus, pacificus, lowryi, and arthingtonae, the last two being transferred from Torodrilus Cook, 1970 and Rhyacodrilus Bretscher, 1901 respectively. Peristodrilus gen.nov. contains the single species montanus. Two other species (M. longisetosus and M. frigidus) will be referred to a new genus within the Phallodrilinae rather than the Rhyacodrilinae. The single member of the Branchiurinae, Branchiura sowerbyi Beddard, 1892 is related to both Rhizodrilus and Bothrioneurum Stolc, 1888 and is included with the Rhyacodrilinae. Telmatodrilus multiprostatus does not usually have its spermathecae in IX but in X as normal, and is not related to Rhizodrilus.The diffuse prostates in some Rhyacodrilinae may have groups of cells penetrating the muscle layers of the atria, somewhat resembling the clustered cells of the Telmatodrilinae, but with the cell bodies still forming a continuous atrial covering.The forward relocation of the spermathecae in Rhizodrilus and their absence in Bothrioneurum seems to be related to the development of large copulatory bursae in XI and the occupation of much of X by atria and vasa deferentia.


1892 ◽  
Vol s2-33 (131) ◽  
pp. 325-341
Author(s):  
FRANK E. BEDDARD
Keyword(s):  

2000 ◽  
Vol 48 (4) ◽  
pp. 433-441 ◽  
Author(s):  
Cs. Székely ◽  
Ariadna Sitjà-Bobadilla ◽  
Pilar Alvarez-Pellitero

Oligochaetes living in the Mijares River close to the Sitjar reservoir, and polychaetes from the brackish and marine waters of a channel flowing into the Mediterranean Sea, both in the province of Castellón (Spain), were examined for the presence of actinosporea. An aurantiactinomyxon was isolated from 60 specimens of the oligochaete Branchiura sowerbyi collected from the river, but no actinospores were isolated from 160 polychaetes collected from the sea channel. The aurantiactinospores were detected by the cell-well plate method. The detected species are not identical with any of the aurantiactinomyxon forms hitherto described in the literature. This is the first report on the occurrence of an actinosporea in Spanish waters.


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