Reproductive Activities of Decapod Crustacea

1947 ◽  
Vol 81 (800) ◽  
pp. 392-398 ◽  
Author(s):  
Martin D. Burkenroad
Keyword(s):  
Decapod Crustacea ◽  
Reproductive Activities

The neurophysiology of respiration in decapod crustacea. II. The sensory system

1969 ◽  
Vol 47 (3) ◽  
pp. 435-441 ◽  
Author(s):  
Valerie M. Pasztor
Keyword(s):  
Connective Tissue ◽  
Sensory Input ◽  
Respiratory Rhythm ◽  
Sensory System ◽  
Nerve Fibers ◽  
Rhythm Generator ◽  
Decapod Crustacea ◽  
New Type

The mechanoreceptors of the respiratory appendage were studied by histological and electrophysiological techniques.A new type of mechanoreceptor is described and named the "oval organ". It consists of a specialized oval patch of cuticle 1–2 mm in length which is traversed by a spine or longitudinal thickening. Closely applied to the cuticle is a pad of connective tissue richly supplied with dendrites from two large nerve fibers. The orientation of the spine and the dendrites ensures that the receptor responds preferentially to certain stresses or foldings of the oval organ. It lies at the base of the scaphognathite on the dorsal surface.No internal proprioceptors were observed. Movements of the appendage are signalled either by the oval organ, epidermal receptors, or hair sensilla.The possible effect of sensory input upon the central respiratory rhythm generator is discussed.

scholarly journals The Pigments of the Decapod Crustacea

1897 ◽  
Vol 21 (4-5) ◽  
pp. 237-257 ◽  
Author(s):  
M. I. Newbigin
Keyword(s):  
Decapod Crustacea

scholarly journals The mating rate of Drosophila suzukii reduction due to reproductive interference from Drosophila melanogaster

2020 ◽  
Author(s):  
Yongzhuo Chen ◽  
Min Zhang ◽  
Wei Hu ◽  
Jing Li ◽  
Pengcheng Liu ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Interspecific Competition ◽  
Population Size ◽  
Egg Laying ◽  
Significant Decline ◽  
Reproductive Interference ◽  
Drosophila Suzukii ◽  
Offspring Number ◽  
Successful Mating ◽  
Reproductive Activities

Abstract Background Drosophila suzukii is widely distributed. Research has revealed that the presence of Drosophila melanogaster can reduce the emergence and egg laying of D. suzukii. However, the reasons for these phenomena have not yet been reported. To investigate this issue, we sought to answer three questions: Can the presence of D. melanogaster reduce the longevity of D. suzukii? Does D. melanogaster dominate in larval interspecific competition with D. suzukii? Does reproductive interference occur between these species; i.e., do individuals of one species (e.g., D. suzukii) engage in reproductive activities with individuals of the other (e.g., D. melanogaster) such that the fitness of one or both species is reduced? Results The results showed that the adult offspring number of Drosophila suzukii was significantly reduced when this species was reared with Drosophila melanogaster. The larval interspecific competition had no significant effects on Drosophila suzukii longevity or population size. Surprisingly, Drosophila melanogaster imposed reproductive interference on males of Drosophila suzukii, which led to a significant decline in the rate of successful mating of the latter species. Conclusions The presence of Drosophila melanogaster causes the population size of Drosophila suzukii to decrease through reproductive interference, and the rate of successful mating in Drosophila suzukii is significantly reduced in the presence of Drosophila melanogaster.

scholarly journals STRATEGI NAFKAH PEREMPUAN NELAYAN TERHADAP PENDAPATAN KELUARGA

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Nina Evi Nur Laila ◽  
Siti Amanah
Keyword(s):  
Family Income ◽  
Financial Security ◽  
Family Needs ◽  
Livelihood Strategy ◽  
Purposive Sampling ◽  
Reproductive Activities

The livelihoods of fishery households are highly vulnerable to fishery sources due to their nature-depending catchments, fishery households in SendangBiru coastal for example. This study focused to analyse the livelihood strategy and contribution of coastal women in SendangBiru to improve their family income. Descriptive and explanatory methods using questionnaire instrument and purposive sampling were used. The responden samples are coastal women who were productively doing activities to obtain extra income for their family. Coastal women of SendangBiru have important roles to improve their family income by spending a lot of time to do productive and reproductive activities. Coastal women’s income contributions bring about significant effects on fishery families’ financial security. Most of coastal women contributions meet half of their family needs.<br />Keywords: livelihood strategy, coastal women, income contribution, family income

scholarly journals Pola Relasi Gender dan Ketangguhan Masyarakat Suatu Kajian Gender dalam UMKM di Kecamatan Tanjung Mutiara, Kabupaten Agam

2020 ◽  
Vol 6 (2) ◽  
pp. 106-121
Author(s):  
Wahyu Pramono ◽  
Jendrius Jendrius ◽  
Zeni Eka Putri
Keyword(s):  
Gender Relations ◽  
Male Involvement ◽  
Living Environment ◽  
Community Level ◽  
Productive Activities ◽  
Or Groups ◽  
The Social ◽  
Reproductive Activities ◽  
And Control ◽  
Micro Enterprises

Abstract: This study analyzes the pattern of gender relations and community resilience in the development of micro enterprises in Tanjung Mutiara District, Agam Regency. The analysis was carried out at the household and community level by conducting interviews with women entrepreneurs, FGDs with women's micro-business groups and limited observation of the conditions of the living environment and the social context of the South Tiku community. The results showed that in general there was a clear division of labor between men and women. Men are involved in temporary productive activities of women in reproductive activities. As a result, women do a greater variety of jobs with a longer duration than men. Productive businesses carried out by women are considered to be only part of the reproductive ladder, so that male involvement and participation are also very low and make women's burdens more severe. Gender relations at the household and community level are relatively equal, this is because women have access and control over resources and also the values ​​and norms that develop in the community facilitate the creation of equality. However, changes in attitudes that are more gender sensitive to the actor's level have not been followed by changes at the community level. It is recommended that an effort to raise awareness for men both at the household and community level is more gender sensitive. Both efforts to provide assistance to micro-enterprises carried out by women need to be optimized especially for individuals or groups of women who really want to develop their businesses.

scholarly journals Mark-Recapture Studies on Co-Occurring Sympecma Fusca (Vander Linden, 1820) and S. Paedisca (Brauer, 1877) (Odonata: Zygoptera: Lestidae)

2014 ◽  
Vol 83 (3) ◽  
pp. 225-234
Author(s):  
Thomas Brockhaus
Keyword(s):  
Czech Republic ◽  
Close Correlation ◽  
Reproductive Behaviour ◽  
Population Estimate ◽  
Mark Recapture ◽  
Male Density ◽  
Reproductive Activities

Abstract Maturation cohorts and reproductive cohorts of the two Sympecma species were studied in Chomutov (Czech Republic) from 2010 to 2013. During individual mark-recapture studies, a total of 705 winter damselflies were recorded, 473 of which were individually marked (375 S. fusca, 98 S. paedisca). The recapture rates in the maturation habitat and in the reproductive habitat were low. The population estimate using CHAPMAN’s method for low recapture rates could not be carried out separately for the two species owing to the low recapture rate of S. paedisca. The proportion of females was greater in the maturation habitat and significantly lower than that of males in the reproductive habitat. The reproductive habitat was predominantly inhabited by territorial males. All the females observed there were engaged in reproductive activities. There was a close correlation between the male density along the shoreline and reproductive activities. S. paedisca was less abundant than S. fusca. No differences between the two species were observed in reproductive behaviour. However, S. paedisca appeared to disperse continuously away from the maturation habitat. Perhaps this species prefers more open areas as maturation and wintering habitats. S. fusca was observed here until October.

scholarly journals Risk-sensitive mating decisions in a visually compromised environment

2009 ◽  
Vol 5 (5) ◽  
pp. 600-602 ◽  
Author(s):  
Bob B. M. Wong ◽  
Marja Järvenpää ◽  
Kai Lindström
Keyword(s):  
Visual Cues ◽  
Perca Fluviatilis ◽  
Reproductive Decisions ◽  
Sand Goby ◽  
European Perch ◽  
Pomatoschistus Minutus ◽  
Risk Sensitive ◽  
Risk Of Predation ◽  
Males And Females ◽  
Reproductive Activities

Reproductive activities are often conspicuous and can increase the risk of predation. Evidence suggests that individuals are capable of responding to predators in a risk-sensitive manner. However, most studies tend to consider only the predator-mediated responses of males and females in isolation and with little regard to differences in local environmental conditions. Here, we experimentally investigate the effects of environmental visibility (turbidity) and predation risk on reproductive decisions in the sand goby, Pomatoschistus minutus , when exposed to a visually oriented predator, the European perch, Perca fluviatilis . We found that gobies were more reluctant to spawn in the predator's presence, although larger males spawned sooner than smaller males. Interestingly, latency to spawning was unaffected by the visual environment, suggesting that gobies may be relying on non-visual cues under turbid conditions.

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