Reproductive cycle and gonadal development of the Atlantic sea urchin Arbacia punctulata in the Gulf of Mexico: changes in nutritive phagocytes in relation to gametogenesis

2020 ◽  
Vol 16 (3) ◽  
pp. 177-194 ◽  
Author(s):  
Eleazar Hernandez ◽  
Omar A. Vázquez ◽  
André Torruco ◽  
Md Saydur Rahman
Keyword(s):  
Gulf Of Mexico ◽  
Sea Urchin ◽  
Reproductive Cycle ◽  
Gonadal Development ◽  
Arbacia Punctulata

Reproductive patterns of the black starry sea urchin Arbacia stellata in Punta Banda, Baja California, Mexico

2019 ◽  
Vol 99 (06) ◽  
pp. 1379-1391 ◽  
Author(s):  
Julia Patricia Díaz-Martínez ◽  
Eugenio De Jesús Carpizo-Ituarte ◽  
Francisco Benítez-Villalobos
Keyword(s):  
Size Distribution ◽  
Sea Urchin ◽  
Reproductive Cycle ◽  
Net Primary Production ◽  
Gonadosomatic Index ◽  
Sampling Site ◽  
Gonadal Development ◽  
Oocyte Size ◽  
Local Conditions ◽  
Positive Correlation

AbstractWidely distributed species such as Arbacia stellata adjust patterns of their life history according to local conditions. In the present study the reproductive cycle of this species was analysed throughout a sampling year. Gonadal development cycle, sex ratio, actual fecundity and oocyte size distribution were characterized and the relationship of these reproductive characteristics with environmental variables such as sea surface temperature, photoperiod, chlorophyll a and net primary production evaluated. Our results showed that A. stellata is a gonochoric sea urchin. Gametogenesis was classified into six stages for both sexes (immature, growth, pre-maturity I, pre-maturity II, mature and spawning) and no synchrony was observed for the gonads between individuals. The female to male ratio was close to 1:1 in most months. The gonadosomatic index (GSI) showed significant differences between sexes or months; however, the highest values were observed during spring, with positive correlation with chlorophyll a. No significant differences were observed in the maturity index (MI) between sexes, with a positive correlation with temperature but negative with chlorophyll. Actual fecundity showed wide variations throughout the year and correlation with chlorophyll a and temperature. Oocyte size distribution was unimodal and the predominant frequency was that of mature oocytes. The reproductive cycle of A. stellata has a semi-continuous pattern for both sexes and partial spawning throughout the year in the sampling site. We observed nutrient assimilation in the gonads during spring and a larger reproductive activity from late summer to early winter.

C-Microtubules in Isolated Mitotic Spindles

1971 ◽  
Vol 9 (3) ◽  
pp. 603-619
Author(s):  
W. D. COHEN ◽  
T. GOTTLIEB
Keyword(s):  
Cross Section ◽  
Sea Urchin ◽  
Cross Sections ◽  
Metaphase Chromosome ◽  
Inverse Relationship ◽  
Mitotic Spindles ◽  
Cylindrical Structure ◽  
Arbacia Punctulata ◽  
Alternate Possibility

Microtubules with incomplete cylindrical structure are present in isolated mitotic spindles of the sea urchin, Arbacia punctulata. In cross-section they appear C-shaped, and are thus similar to the ‘C-microtubules’ or ‘C-filaments’ observed previously in other systems. The C-microtubules are not uniformly distributed within isolated spindles, but are typically numerous in the interzonal region of anaphase spindles and in the metaphase chromosome ‘plate’. In chromosome-to-pole regions they are seen much less frequently, and microtubules with the usual O-configuration predominate. Counts of C- and O-microtubules in anaphase spindle cross-sections of known location show an inverse relationship between the number of C-microtubules present and the total number of microtubules present. The observations suggest that the C-microtubules are not simple artifacts of fixation or isolation, but rather may represent a stage of microtubule disassembly which occurs in the interzone during isolation or during anaphase in vivo. The alternate possibility of assembly is not excluded, however. The significance of C-microtubules is further discussed with respect to their occurrence in other systems, and to potential differences between mitotic microtubules.

Gonadal development and the reproductive cycle of the geoduck clam (Panopea japonica) in the Sea of Japan

Aquaculture ◽  
2021 ◽  
pp. 737606
Author(s):  
Wen Zhao ◽  
Ying Li ◽  
Yuhang Wang ◽  
Xinghong Luo ◽  
Qidi Wu ◽  
...  
Keyword(s):  
Sea Of Japan ◽  
Reproductive Cycle ◽  
Gonadal Development ◽  
The Sea Of Japan

scholarly journals THE EXTRACELLULAR RELEASE OF ECHINOCHROME

1946 ◽  
Vol 29 (5) ◽  
pp. 267-275 ◽  
Author(s):  
Herbert Shapiro
Keyword(s):  
Sea Urchin ◽  
Sea Water ◽  
Potassium Content ◽  
Red Pigment ◽  
Anaerobic Conditions ◽  
Outward Diffusion ◽  
Arbacia Punctulata ◽  
Extracellular Release

A study was made of the diffusion of the red pigment echinochrome from the eggs of the sea urchin, Arbacia punctulata, into sea water. Unfertilized eggs retained their pigment, over periods of hours. Outward diffusion of pigment from unfertilized eggs normally is entirely negligible, or does not occur at all. Enchancing the calcium or potassium content of the artificial sea water (while retaining isosmotic conditions) did not induce pigment release. Under anaerobic conditions, unfertilized eggs release pigment in small quantities. Fertilization alone brings about echinochrome release. Fertilized eggs invariably released pigment, whether in normal sea water, or sea water with increased calcium or potassium. This diffusion of the pigment began during the first cleavage, possibly soon after fertilization. The pigment release is not a consequence solely of the cell's permeability to echinochrome (or chromoprotein, or other pigment combination) but is preceded by events leading to a release of echinochrome from the granules in which it is concentrated within the cell. These events may be initiated by activation or by anaerobiosis. The phenomenon was not due to cytolysis.

Pinocytosis in fertilized sea urchin (Arbacia punctulata) eggs

1984 ◽  
Vol 231 (3) ◽  
pp. 413-422 ◽  
Author(s):  
Christopher P. Carron ◽  
Frank J. Longo
Keyword(s):  
Sea Urchin ◽  
Arbacia Punctulata
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