scholarly journals Behavioural response of the mud lobster, Thalassina anomala Herbst, 1804 (Decapoda, Gebiidea), to different trapping devices

Crustaceana ◽  
2019 ◽  
Vol 92 (3) ◽  
pp. 353-371 ◽  
Author(s):  
Mohammad S. Hossain ◽  
Japar S. Bujang ◽  
Abu Hena M. Kamal ◽  
Muta H. Zakaria ◽  
Aidy M. Muslim

Abstract The behavioural response of the mud lobster, Thalassina anomala Herbst, 1804, to different trapping devices (TD), was studied in the mangrove areas of Sibuti, Sarawak, East Malaysia. Nine different TDs were deployed in this study. Observations revealed that there were no differences in response, neither due to the various types of mound, or as a result of the different TDs: rather, the lobsters either avoided, or obstructed those TDs. Detailed observations revealed that the mud lobsters showed skilled avoidance by either moving freshly dug, moist mud into the TD-types made of bamboo and plastic, or moved the fishing net out of the burrow when it was obstructed by such a type of TD. The damaged parts of the mound caused by deployment of the TD were successfully reconstructed or rebuilt by the mud lobster, using moist mud from the bottom of their tunnel. There was no particular period determined, i.e., neither by day nor at night, when the mud lobsters repaired or rebuilt their opened or otherwise disturbed burrows.

2016 ◽  
Vol 66 (3) ◽  
pp. 507-526 ◽  
Author(s):  
Tatiana Blinova ◽  
Vladimir Markov ◽  
Viktor Rusanovskiy

The purpose of the study is to conduct a statistical analysis and to perform a quantitative assessment of the degree and the dynamics of the interregional differences in youth unemployment in Russia between 2005 and 2013. We decompose the interregional differentiation into “within-group” and “between-group” differences. We also analyse the dynamics of the within-group and between-group differences and estimate their contribution to changes in the interregional differentiation of youth unemployment. Additionally, we estimate the degree and the dynamics of the interregional differences of the youth labour market in Russia in times of crisis and recovery growth. The results show a reduction in the interregional differences in unemployment rates between 2005 and 2008, while in 2009–2013, the interregional differentiation of the labour market increased. We found that the socio-economic effects of youth unemployment, as well as the behavioural response to economic shocks in the age groups of 15–19 and 20–29 years were significantly different.


1969 ◽  
Vol 45 (1) ◽  
pp. 99-109 ◽  
Author(s):  
M. J. CARRICK ◽  
J. N. SHELTON

SUMMARY Experiments were conducted to examine the behavioural response of spayed heifers to oestrogen, and its modification by progesterone. In two groups of heifers, the median effective doses (MED) of oestradiol benzoate (ODB) were 121 and 132 μg. Repeated doses of ODB at physiological levels did not induce a state of refractoriness; in this respect the heifer is dissimilar to the ewe. However, repeated doses of 10 mg. ODB induced refractoriness to 400 μg. ODB. When such refractory heifers were treated with 10 mg. progesterone/day for 5 days, they showed a normal response to 400 μg. ODB given 3 days later. This return to normal sensitivity was not sustained, and pretreatment with progesterone was necessary for a normal response to subsequent small doses of ODB. The transient removal of the refractory state appears not to be due to a simple synergistic effect of residual progesterone, but to an effect of preconditioning a neural centre to respond to oestrogen. Increasing the duration of pretreatment with progesterone beyond 5 days did not result in a greater sensitivity to ODB. Pretreatment with progesterone in heifers not made refractory to ODB did not result in an increased sensitivity to ODB. Moreover, up to 7 days after termination of the progesterone treatment, the response to ODB was reduced and the slope of the dose-response line was less steep than when ODB was injected alone. The reduction of the response was more pronounced with 40 mg. progesterone/day than with 10 mg. The possible significance of these results in intact animals is discussed.


2021 ◽  
Vol 778 ◽  
pp. 146320
Author(s):  
Trevor J. Hamilton ◽  
Nicole Hurst Radke ◽  
Jasmin Bajwa ◽  
Shayna Chaput ◽  
Martin Tresguerres

2020 ◽  
Vol 8 (1) ◽  
pp. 1
Author(s):  
Giacomo Riggio ◽  
Chiara Mariti ◽  
Valeria Sergi ◽  
Silvana Diverio ◽  
Angelo Gazzano

In mammals, serotonin (5-HT) levels depend on the availability of tryptophan (TRP). Low 5-HT concentrations have been linked to behavioural disorders in dogs. This study aimed at investigating possible differences in dogs’ serum TRP and 5-HT concentrations according to their behavioural response to a potentially stressful procedure. Thirty-nine physically healthy shelter dogs, 15 females and 24 males, mean age = 5.6 years, were categorized by a certified veterinary behaviourist according to their behavioural response to medical examination and blood collection, in: relaxation, stress signals, tension without growling, tension with growling, escape attempts, and aggression attempts. Extraction and quantification of 5-HT and TRP were performed using a HLPC method. Data were statistically analysed, applying Chi-square and Spearman tests. Results showed no significant difference in TRP (χ2 = 2.084, p = 0.555) nor 5-HT (χ2 = 0.972, p = 0.808) serum concentrations among different categories of dogs; however, some categories were underrepresented (relaxation = 20.5%, stress signals = 30.8%, tension without growling = 43.6%, tension with growling = 5.1%, escape attempts = 0%, aggression attempts = 0%). No correlation between serum TRP and 5-HT concentrations was found (ρ = 0.086, p = 0.602). Serum 5-HT levels do not seem to be associated with dogs’ behavioural response to a stressful situation nor with serum TRP concentrations. The relationship between serum TRP and 5-HT concentrations and behaviour needs further research.


ZooKeys ◽  
2018 ◽  
Vol 760 ◽  
pp. 89-112 ◽  
Author(s):  
Peter K. L. Ng ◽  
Paul Y. C. Ng

Seven species of freshwater crabs from three families are recorded from and around the Danum Valley Conservation Area in Sabah, Malaysian Borneo: Thelphusulacapillodigitus sp. n., Thelphusuladicerophilus Ng & Stuebing, 1990, Arachnothelphusaterrapes Ng, 1991, Terrathelphusasecula Ng & Tan, 2015, Parathelphusavalida Ng & Goh, 1987 (new record) (Gecarcinucidae); Isolapotamoningeri Ng & Tan, 1998 (Potamidae); and Geosesarmadanumense Ng, 2002 (Sesarmidae). The new species of Thelphusula Bott, 1979, can be distinguished from all congeners by a unique combination of morphological features, most notably the presence of dense patches of short setae on the fingers of the adult male chelipeds, as well as the structure of the male first gonopod. Arachnothelphusaterrapes is confirmed to be a phytotelm species. A key to all species in the conservation area is provided.


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