Functional anatomy of the female reproductive system of the American lobster (Homarus americanus)

2018 ◽  
Vol 279 (11) ◽  
pp. 1603-1614 ◽  
Author(s):  
Michel Comeau ◽  
Kadra Benhalima
2019 ◽  
Vol 97 (7) ◽  
pp. 650-653
Author(s):  
Michel Comeau ◽  
Kadra Benhalima

American lobsters (Homarus americanus H. Milne Edwards, 1837) settling to the bottom after their pelagic larval stage are sexually undifferentiated. Based on stereomicroscope observations, the female’s gonopore first appeared for lobsters about 13 mm carapace length (CL) and the dimorphism of the first pair of male pleopods was first observed at about 15 mm CL. Based on histological observations, the internal reproductive system for both males and females began differentiating at sizes ≥20 mm CL. The vasa deferentia were observed for males >30 mm CL indicating that the male reproductive system is fully formed. For females, the ovaries were observed at sizes ≥20 mm CL, but the oviducts were not detected in animals <36 mm CL. The male reproductive system is morphologically complete at a substantially smaller CL than for females.


2016 ◽  
Vol 557 ◽  
pp. 177-187 ◽  
Author(s):  
MD McMahan ◽  
DF Cowan ◽  
Y Chen ◽  
GD Sherwood ◽  
JH Grabowski

2020 ◽  
Vol 641 ◽  
pp. 159-175
Author(s):  
J Runnebaum ◽  
KR Tanaka ◽  
L Guan ◽  
J Cao ◽  
L O’Brien ◽  
...  

Bycatch remains a global problem in managing sustainable fisheries. A critical aspect of management is understanding the timing and spatial extent of bycatch. Fisheries management often relies on observed bycatch data, which are not always available due to a lack of reporting or observer coverage. Alternatively, analyzing the overlap in suitable habitat for the target and non-target species can provide a spatial management tool to understand where bycatch interactions are likely to occur. Potential bycatch hotspots based on suitable habitat were predicted for cusk Brosme brosme incidentally caught in the Gulf of Maine American lobster Homarus americanus fishery. Data from multiple fisheries-independent surveys were combined in a delta-generalized linear mixed model to generate spatially explicit density estimates for use in an independent habitat suitability index. The habitat suitability indices for American lobster and cusk were then compared to predict potential bycatch hotspot locations. Suitable habitat for American lobster has increased between 1980 and 2013 while suitable habitat for cusk decreased throughout most of the Gulf of Maine, except for Georges Basin and the Great South Channel. The proportion of overlap in suitable habitat varied interannually but decreased slightly in the spring and remained relatively stable in the fall over the time series. As Gulf of Maine temperatures continue to increase, the interactions between American lobster and cusk are predicted to decline as cusk habitat continues to constrict. This framework can contribute to fisheries managers’ understanding of changes in habitat overlap as climate conditions continue to change and alter where bycatch interactions could occur.


1972 ◽  
Vol 70 (2) ◽  
pp. 396-408 ◽  
Author(s):  
K.-D. Schulz ◽  
H. Haarmann ◽  
A. Harland

ABSTRACT The present investigation deals with the oestrogen-sensitivity of the female reproductive system during the neonatal period. Newborn female guinea pigs were used as test animals. At different times after a single subcutaneous injection of a physiological dose of 0.1 μg or an unphysiologically high dose of 10 μg 17β-oestradiol/100 g body weight, the RNA- and protein-synthesis was examined in the hypothalamic region, pituitary, cerebral cortex, liver, adrenal gland, ovary and uterus. With a physiological dose an increase in organ weight, protein content, RNA-and protein-synthesis was found only in the uterus. These alterations turned out to be dose-dependent. In addition to the findings in the uterus an inhibition of the aminoacid incorporation rate occurred in the liver following the injection of the high oestradiol dose. As early as 1 hour after the administration of 0.1 μg 17β-oestradiol an almost 100% increase in uterine protein synthesis was detectable. This result demonstrates a high oestrogen-sensitivity of this organ during the neonatal period. All the other organs of the female reproductive system such as the hypothalamus, pituitary and ovary did not show any oestrogen response. Therefore the functional immaturity of the uterus during post partem life is not the result of a deficient hormone sensitivity but is correlated with the absence of a sufficient hormonal stimulus at this time. The investigation on the effects of actinomycin resulted in different reactions in the uterus and liver. In contrast to the liver a paradoxical actinomycin effect was found in the uterus after treatment with actinomycin alone. This effect is characterized by a small inhibition of RNA-synthesis and a 50% increase in protein synthesis. The treatment of the newborn test animals with actinomycin and 17β-oestradiol together abolished the oestrogen-induced stimulation of the uterine RNA-and protein-synthesis. Consequently, the effect of oestrogens during the neonatal period is also connected with the formation of new proteins via an increased DNA-directed RNA-synthesis.


2017 ◽  
Vol 27 (3) ◽  
pp. 250-265 ◽  
Author(s):  
Volodymyr Yu. Prokopyuk ◽  
◽  
Olga V. Grischenko ◽  
Oleksandra V. Prokopyuk ◽  
Nadiia O. Shevchenko ◽  
...  

2020 ◽  
Vol 6 (1) ◽  
pp. 23-31
Author(s):  
M. Alisherova ◽  
◽  
M. Ismailova

Currently, there are no standard approaches to monitoring patients with ovarian cancer (OC). While the role of ultrasound (US) has been identified in the primary diagnosis of OS, it is still controversial during the subsequent surgical treatment of OC. In world statistics, ovarian cancer is consistently among the four main localizations of malignant tumors of the female reproductive system, along with tumors of the breast, body and cervix.


2009 ◽  
Vol 22 (2) ◽  
pp. 109-124 ◽  
Author(s):  
Zaher A. Radi ◽  
Rosemary A. Marusak ◽  
Dale L. Morris

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