Sea-urchin Embryo Bioassay for in situ Evaluation of the Biological Quality of Coastal Seawater

2001 ◽  
Vol 52 (1) ◽  
pp. 29-32 ◽  
Author(s):  
R. Beiras ◽  
E. Vázquez ◽  
J. Bellas ◽  
J.I. Lorenzo ◽  
N. Fernández ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Coastal Seawater ◽  
Biological Quality ◽  
Sea Urchin Embryo

Ultrastructural preservation of the cortical region of sea urchin embryonic ectoderm

1987 ◽  
Vol 45 ◽  
pp. 942-943
Author(s):  
C. Nislow ◽  
R. G. Summers ◽  
J. B. Morrill
Keyword(s):  
Sea Urchin ◽  
Osmium Tetroxide ◽  
Lytechinus Variegatus ◽  
Cortical Region ◽  
Cellular Interactions ◽  
Transmission Electron ◽  
Sea Urchin Embryo ◽  
Immunocytochemical Techniques ◽  
Embryonic Ectoderm

Recent studies using immunocytochemical techniques have renewed interest in the sea urchin embryo as a model system for development, particularly with respect to cellular interactions during morphogenesis. The bulk of these studies have been performed with the light microscope (LM) using fluorescently labeled antibodies, (i.e. Wessel and McClay, 1986)Transmission electron microscopy (TEM) reveals that the cortex of the embryonic ectoderm includes membranous vesicles, yolk platelets, mitochondria, Golgi complexes, and the hyaline layer. The proximity of these compartments to the cell surface warrants a detailed study of their ultrastructure.We have examined the quality of preservation with simultaneous and sequential fixation using glutaraldehyde and osmium tetroxide. Also examined are the effects of several additives and the quality of preservation with Bouin's fixative, which has been used in immunocytochemical preparations.Embryos of Lytechinus variegatus were fertilized and reared according to the methods of Morrill and Santos (1986).

scholarly journals Reproduction of the sea urchin Tripneustes depressus (Camarodonta: Toxopneustidae) in Bahía de La Paz, Baja California Sur, Mexico

2021 ◽  
Vol 69 (Suppl.1) ◽  
pp. 202-218
Author(s):  
Ailet Vives ◽  
Tamara Rubilar ◽  
María-Dinorah Herrero-Pérezrul ◽  
Bertha-Patricia Ceballos-Vázquez
Keyword(s):  
Sea Urchin ◽  
Baja California ◽  
Gonad Development ◽  
Reproductive Season ◽  
Baja California Sur ◽  
Test Diameter ◽  
La Paz ◽  
Wet Weight

Introduction: Sea urchin gonads (roe or uni) are considered a culinary delicacy worldwide. However, only a few species are considered edible and commercialized. The sea urchin Tripneustes depressus has generated the interest of producers in Baja California Sur, Mexico, due to the quality of its gonads. A biological basis for designing a management strategy is key to consider its commercial exploitation. Objective: To determine the reproductive season of T. depressus through description of the gonad stages and reproductive cycle, and to establish its relationship with environmental factors. Methods: We collected monthly samples (October 2016-September 2017), recording in-situ temperature and photoperiod. We evaluated a sample of 1 055 specimens for demographic characteristics, using total weight (g) and test diameter (cm). We also did a histological analysis of gonads from 178 individuals. Results: Average test diameter was 9.70 ± 0.03 cm (5-12.50 cm). Based on the proportion into the gonad of sexual (gametes) and somatic (nutritive phagocytes) cells, we propose five gonad stages (growing, premature, mature, spawning, and intergametic) for both sexes. There were two times of the year when gonads were heaviest and closely corresponded to the growing stage, coinciding with the highest proportions of nutritive phagocytes. Gonad development (growing and premature stages) peaks in the months with the longest daylight periods, with spawning in the shortest daylight periods. Conclusions: Gonad wet weight and adjusted gonad weight are good indicators of the reproductive season of T. depressus. The lowest gonad wet weights were matched the spawning peak in the shortest daylight period (January and March).

Improved sea-urchin embryo bioassay for in situ evaluation of dredged material

Ecotoxicology ◽  
2009 ◽  
Vol 18 (8) ◽  
pp. 1051-1057 ◽  
Author(s):  
M. J. Salamanca ◽  
N. Fernández ◽  
A. Cesar ◽  
R. Antón ◽  
P. Lopez ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Dredged Material ◽  
Sea Urchin Embryo

Pengaruh Jenis Co-Solvent terhadap Rendemen dan Mutu Biodiesel secara Transesterifikasi In Situ Menggunakan Radiasi Gelombang Mikro

2016 ◽  
Vol 10 (2) ◽  
pp. 119-126
Author(s):  
Mahlinda Mahlinda ◽  
Fitriana Djafar
Keyword(s):  
Catalyst Concentration ◽  
Maximum Yield ◽  
Acid Value ◽  
Experimental Result ◽  
In Situ Transesterification ◽  
Yield And Quality ◽  
Solvent Type ◽  
Biodiesel Quality

The main purpose of this research was to observer effect co-solvent type (n-Hexane, chloroform and without co-solvent)  toward yield and quality of biodiesel via in situ transesterification process using microwave irradiation. The process was studied at microwave power 450 watt, reaction time 4 minutes, methanol to seed ratio 25:1 and catalyst concentration 5%. The physicochemical parameters of the biodiesel produced such as viscosity, density and acid value were analysed and compared with the SNI 7182-2012 standard. The experimental result showed the maximum yield biodiesel 78,32% obtained by using co-solvent chloroform.Test result of physicochemical properties (viscosity, density and acid value) of biodiesel products using co solvent n-Hexane, chloroform and without co solvent showed that these products conform to the SNI 7182-2012 standars. The type of co-solvent only affectedon biodiesel yield dan not affected on biodiesel quality (viscosity, density and acid value).  ABSTRAKTujuan penelitian ini adalah untuk mempelajari pengaruh jenis co-solvent (n-Hexane, chloroform dan tanpa co-solvent) terhadap rendemen dan mutu biodiesel secara trasesterifikasi in situ menggunakan radiasi gelombang mikro. Proses dilakukan pada daya gelombang mikro 450 watt, waktu reaksi 4 menit, perbandingan berat metanol terhadap bahan baku 25:1 dan jumlah katalis 5%. Parameter fisiko kimia dari produk biodiesel seperti viskositas, densitas dan angka asam di analisa dan dibandingkan dengan standar SNI 7182-2012 tentang biodiesel. Hasil penelitian menunjukkan rendemen maksimum biodiesel sebesar 78,32% diperoleh dengan menggunakan co-solvent chloroform. Hasil pengujian  karakteristik fisiko kimia (viskositas, densitas dan angka asam) dari produk biodiesel menggunakan co-solvent n-Hexane, chloroform dan tanpa co-solvent menunjukkan bahwa semua parameter ini masih memenuhi standar SNI 1782-2012 tentang biodiesel. Jenis co-solvent hanya berpengaruh pada rendemen biodiesel dan tidak berpengaruh terhadap mutu biodiesel (viskositas, densitas dan bilangan asam).Kata kunci: co-solvent, in situ transesterifikasi, microwave, rendemen, mutu   

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