THE SYSTEM OF PIT ORGAN LINES IN GYMNARCHUS NILOTICUS

1945 ◽  
Vol 26 (1-3) ◽  
pp. 1-8 ◽  
Author(s):  
Torsten Pehrson
2020 ◽  
Vol 11 ◽  
Author(s):  
Pramod KC ◽  
Xi Chu ◽  
Pål Kvello ◽  
Xin-Cheng Zhao ◽  
Gui-Rong Wang ◽  
...  

2018 ◽  
Vol 40 (5) ◽  
pp. 1367-1380 ◽  
Author(s):  
Chukwujindu M. A. Iwegbue ◽  
Diemiruaye Odogbor ◽  
Francis E. Egobueze ◽  
Onoriode O. Emoyan ◽  
Godswill O. Tesi ◽  
...  

Heliyon ◽  
2020 ◽  
Vol 6 (9) ◽  
pp. e04959
Author(s):  
Patrick Omoregie Isibor ◽  
Bamidele Akinsanya ◽  
Temitope Sogbamu ◽  
Fatsuma Olaleru ◽  
Akeredolu Excellence ◽  
...  

The occurrence of mutants of Drosophila melanogaster distinguished by the absence or structural modification of the antennae provides a means of assessing the role of the antennae with respect to the reception of various classes of stimuli. Antennaless ( A 0 ) phenotypes of antennaless stock fail to respond to those chemical stimuli which lead the fly to its food. Their temperature reactions are normal, and their humidity responses are opposite to those of somatically wild-type flies of the same stock or of wild-type controls. Aristapedia ( ss a ), which have leg-like antennae equipped with surface pegs and cones of supposed sensory function present in the normal antenna but absent in the normal leg, respond to chemical stimuli and humidity differences. As compared with that of normal flies, the olfactory response of aristapedia ( ss a ) is somewhat less intense, the humidity reaction being somewhat stronger. These mutants do not give the characteristic responses evoked by thermal stimuli both in normal flies and antennaless phenotypes. The outstanding histological differences between the structure of the antenna of aristapedia and that of wild-type flies is the absence of the pit organ. It thus seems that the pit organ is not essential to the olfactory response and plays no essential part in the humidity response. Since antennaless ( A 0 ) responds normally to thermal stimuli, none of the putative sense organs of the antennae are essential to the recognition of temperature differences, and since aristapedia ( ss a ) responds more weakly to chemical stimuli than do normal flies, the pit organs may well be long-distance chemoreceptors. What is more certain is that either the peg-like organs or the cones on the surface of the distal joint of the antennae or both are chemoreceptors. The same remark is equally applicable to the perception of humidity differences. Experiments here recorded do not justify the identification of the function of one or other type of sensilla with one or the other type of receptivity. While it is unjustifiable to exclude the possibility that short-distance chemical stimuli play a part in the attraction of flies of opposite sex, it appears that the main role of chemoreceptivity in relation to the mating behaviour of D. melanogaster is to ensure the aggregation of flies of both sexes in situations where food is available and sexual congress can be evoked by other forms of stimulation.


2013 ◽  
Vol 353 (3) ◽  
pp. 399-408 ◽  
Author(s):  
Xin-Cheng Zhao ◽  
Qing-Bo Tang ◽  
Bente G. Berg ◽  
Yang Liu ◽  
Yan-Ru Wang ◽  
...  

2015 ◽  
Vol 78 (3) ◽  
pp. 554-560 ◽  
Author(s):  
CHUKWUJINDU M. A. IWEGBUE ◽  
GODSWILL O. TESI ◽  
LORETTA C. OVERAH ◽  
FRANCISCA I. BASSEY ◽  
FRANK O. NWADUKWE ◽  
...  

The concentrations and profiles of polycyclic aromatic hydrocarbons (PAHs) in 10 popular fish species in the Nigerian market were determined with a view to providing information on the health hazards associated with the consumption of these fish species. The concentrations of PAHs were measured by gas chromatography–mass spectrometry after extraction by ultrasonication with acetone-dichloromethane and clean up. The concentration ranges of the Σ16 PAHs were 20 to 39.6 μg kg−1 for Parachanna obscura (African snake head), 6.8 to 532.3 μg kg−1 for Oreochromis niloticus (tilapia), 7.4 to 91.1 μg kg−1 for Gymnarchus niloticus (Asa), 13.1 to 34.1 μg kg−1 for Sebastes fasciatus (red fish), 11.2 to 80.0 μg kg−1 for Gadus morhua (cod), 23.9 to 34.6 μg kg−1 for Chrysicthys nigrodigitatus (silver cat fish), 63.4 to 131.4 μg kg−1 for Sardinella aurita (sardine), 22 to 52.9 μg kg−1 for Trachurus trachurus (Atlantic horse mackerel), 21.0 to 63.7 μg kg−1 for Scomber scombrus (mackerel), and 27.7 to 44.5 μg kg−1 for Pseudotolithus senegalensis (croaker). Benzo[a]pyrene occurred in 23% of these fish samples at concentrations above the European Union permissible limit of 2.0 μg kg−1. The calculated margins of exposure based on the indicators for occurrence and effects of PAHs were greater than 10,000 indicating no potential risk for the consumers of the species evaluated in this study.


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