I´m using thermal shocks but I would like to know if there are more effective options. Thank you.
Hello Tahere. Thank you for answering. So, may you help me with this issue?
Can you tell me which species you are working with, their usual habitat and spawning period, are they hermaphrodite, and what you wish to do with the resulting gametes? This makes a difference to the technique.
Hello Dawn. I'm currently working with Pinna nobilis. This species is hermaphrodite and its spawning season goes from June to late September. My purpose is to fecondate the gametes to achieve the production of juvenile individuals.
I would try serotonin (5-Hydroxytryptamine; 5-HT) first. This is a standard chemical inducer in bivalves. Serotonin is fairly inexpensive. If 5-HT does not work, you can also try antidpressants like Prozac (fluoxetine). You can also combine the chemical treatments with thermal shock.
Thank you very much Peter. I´m going to try with serotonin first. Again thank you for your time.
1rst, try an decrease of the salinity in same time that you will increase a lit bit the seawater temperature.
In the fields, most of the benthic anaimals living in the indopacifi tropics expluse their eggs at the beginning of the wet and warm season.
Saiy me the result.
Prof. Dr. B.A. Thomassin, Marseilles, France
Sergio, en unas prácticas que hice con Mytilus californianus en el Pacífico acostumbrabamos por practicidad dejar desde la colecta (digamos 3 pm) y toda la noche al aire libre (pero con techo) la muestra de organismos. A primera hora de la mañana (7-8 am) los regresabamos al agua fría (aprox. 10° C) y no esperabamos más de 1 hr cuando ya teníamos resultados. Digamos que es shock térmico aunado al estrés por exposición al aire. No he tenido buenos resultados con ostión del Atlántico, parece ser que cada especie tiene sus particularidades, pero dado que la especie que manejas es un mejillón bien pudieras probar. Saludos.
Dear Bernard. I will also try the decrase of salinity. Merci beaucoup pour votre réponse.
Estimado Víctor. Gracias por su comentario y por su tiempo. Tengo entendido que introducirlos en lugares refrigerados "en seco" durante varias horas funciona muy bien con ciertos bivalvos. Sin embargo con P. nobilis lo he intentado y no ha funcionado demasiado bien. El problema es que esta especie no permanece cerrada como puede hacerlo Mytilus por ejemplo. Siempre tiene ciertas pérdidas de agua o incluso llega a abrirse cuando es transportada en seco. Lo que si me ha funcionado muy bien (y con otros bivalvos también ocurre) es el shock mecánico, bien agitándolos brevemente o limpiándo sus valvas con cepillos. Un saludo cordial y de nuevo gracias.
I worked on fertilisation success and sperm dilution effects with temperate and Antarctic scallops, limpets and clams. I found temperature variation worked with temperate species if they were very ripe. However, for the hermaphrodites held at aquaria in Antarctica, I was unsuccessful with temperature, salinity and serotonin shock, and I had to resort to strip spawning by dissection of the gonads. I did achieve good fertilisation success after strip spawning and mixing the gametes from different individuals in small vials at varying sperm concentrations, but kept them all at ambient salinity and water temperature....however, note that sperm concentration and salinity is very important for achieving success, too much sperm will cause polyspermy and abnormalities, and salinity will affect success as well. You may want to bear that in mind if manipulating fertilisation in small containers. There are a good number of publications on the subject of fertilisation success and sperm dilutions. Good luck.
Thank you for your reponse Dawn. In my case the thermal shock usually works but sometimes we need to obtain gametes and it is not enough. Moreover, we cannot sacrifice the individuals because is an endangered species thus protected. I will try firstly with serotonine combined with salinity and temperature variation.
Again thank you for your advices.
If all else fails, try loud rock music or singing to them....it worked for UK bivalves....but one does anything to make a PhD experiment work!
Haha. I think could be worst if i sing...anyway you are right all ideas should be considered. Thanks again Dawn.
May I recommend you dissolve serotonin at 1 or 2 millimolar and expose the bivalves to the external solution. If this does not work, you can try injecting the serotonin directly into the foot. I am not familiar with the species you are working with, but you may have to cut a small hole or notch in the shell to gain access to the foot.
Dear Mostafa and Peter. Many thanks to both of you for your responses.
Dear Sergio,
I'm agree with Dawn. There are the difference about the mechanism of oocytic maturation on bivalve which is gonochorist (I studied with oyster Crassostre gigas) and those of hermaphrodites (as scallop, I studied by using Pecten maximus). So, which species that you work? It define the method that you must used. For gonochorist, temperature, usually works. But not for the hermaphodites (case of Pecten maximus).Please see the abstract of my old works as attached.
Hopely that could help you.
Best regards,
Ita.
Dear Ita,
Thank you very much for your reponse. I´m currently working on Pinna nobilis and i would really appreciate to read your complete manuscripts about this topic. My mail addres is [email protected]
Thank you very much in advance!
Sergio
Dear Sergio,
I attached the complete manuscript as you mention.
Hopely that could useful for you.
Ita
Thank you very much Ita!
Do not hesitate if yo need anything from me.
Best regards,
Sergio
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