Estudio preliminar sobre una posible inhibición dopaminérgia en la reproducción del lenguado senegalés (Solea senegalensis)

El objetivo del presente estudio fue evaluar el efecto del sistema dopaminérgico sobre la reproducción del lenguado senegalés (Solea senegalensis). Para ello, reproductores de lenguado senegalés nacidos y criados en cautividad (generación F1) fueron tratados con 1) GnRHa, 2) inhibidor dopaminérgico (pimozide) o 3) un tratamiento combinado (GnRHa + pimozide). El efecto de los tratamientos se evaluó a nivel de producción de huevos y esperma (cantidad y calidad); además se estudió el efecto sobre niveles plasmáticos de esteroides sexuales y desarrollo gonadal (histología). Las hembras no mostraron una estimulación en la ocurrencia de puestas por el tratamiento combinado GnRHa + pimozide respecto a aquellas tratadas solo con GnRHa. Sin embargo, los machos que recibieron el tratamiento combinado mostraron una mayor estimulación en la producción de esperma y en el grado de maduración testicular respecto a aquellos que recibieron solo GnRHa o pimozide. Los resultados indican que el sistema dopaminérgico no parece ejercer una acción fuerte sobre la ocurrencia de puestas en hembras, aunque podría estimular la espermiación en machos de lenguado senegalés.Preliminary study on dopaminergic inhibition in Senegalese sole reproduction (Solea senegalensis) The aim of the present study was to evaluate the effect of the dopaminergic system on Senegalese sole (Solea senegalensis) reproduction. For this purpose, Senegalese sole breeders hatched and raised in captivity (F1 generation) were treated with 1) GnRHa, 2) a well-known dopaminergic inhibitor (pimozide) or 3) a combined treatment (GnRHa + pimozide). The effect of each treatment was determined by studying spawning occurrence and sperm (quantity and quality); in addition, effects on sex steroids levels and on gonadal development (histology) were also considered. Females did not show any improvement of spawning occurrence by combining GnRHa and pimozide respect to those females treated only with GnRHa. However, males which received the combined treatment showed a greater stimulation of sperm production and testicular maturity than those males treated with a single GnRHa or pimozide treatment. Our results indicate that dopaminergic system do not seem to play a strong action on eggs spawning in females, but may stimulate spermiation in Senegalese sole males

Sole farming: nearly there but not quite?

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Characterisation of plasmatic B-esterases in bottlenose dolphins (Tursiops truncatus) and their potential as biomarkers of xenobiotic chemical exposures

9 pages, 5 pages, 3 figures, supplementary data https://doi.org/10.1016/j.envpol.2022.120149.-- Data availability: Data will be made available on requestA total of 164 blood samples from 16 clinically healthy bottlenose dolphins (Tursiops truncatus), were obtained from an aquarium in Spain between 2019 and 2020, as part of their preventive medicine protocol. In addition to conventional haematological and biochemical analyses, plasmatic B-esterase activities were characterised to determine the potential application of such analyses in wild counterparts. The hydrolysis rates for the substrates of acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and carboxylesterase (CE) activity in plasma were measured, the last using two commercial substrates, p-nitrophenyl acetate (pNPA) and p-nitrophenyl butyrate (pNPB). Activity rates (mean ± SEM in nmol/min/mL plasma) were (in descending order): AChE (125.6 ± 3.8), pNPB-CE (65.0 ± 2.2), pNPA-CE (49.7 ± 1.1) and BuChE (12.8 ± 1.3). These values for dolphins are reported in here for the first time in this species. Additionally, the in vitro sensitivity of two B-esterases (AChE and pNPB-CE) to chemicals of environmental concern was determined, and the protective role of plasmatic albumin assessed. Out of the B-esterases measured in plasma of dolphin, AChE activity was more responsive in vitro to pesticides, while CEs had a low response to plastic additives, likely due to the protective presence of albumin. However, the clear in vitro interaction of these environmental chemicals with purified AChE from electric eels and recombinant human hCEs (hCE1 and hCE2) and albumin, predicts their impact in other tissues that require in vivo validation. A relationship between esterase-like activities and health parameters in terrestrial mammals has already been established. Thus, B-esterase measures could be easily included in marine mammal health assessment protocols for dolphins as well, once the relationship between these measures and the animal's fitness has been establishedTo the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe

Effect of hormonal treatments on senegalese sole sperm quality

Trabajo presentado en el 5th International Workshop on the Biology of Fish Gametes, celebrado en Ancona (Italia), del 7 al 11 de septiembre de 2015Senegalese sole (Solea senegalensis) F1 reproduction still presents some constraints that difficult the use of these individuals to guarantee further production. F1 breeders do not reproduce naturally in the tank, and therefore, gamete collection and artificial fertilization is a procedure that has been developed (Rasines et al., 2012) and is being adapted to fish farms. One of the principal problems is the difficulty in obtaining sperm due to their low volume and concentration, a characteristic specific in this species (wild males) but more pronounced in F1 males. Some hormonal treatments already proved to be efficient in slightly increasing sperm volume (Guzmán et al., 2011), but there are still some gaps on the evaluation of this contribution. No reports on the quality of sperm has been delivered so far that guarantee a safety use of this material, especially if some management techniques such as cryopreservation will be applied. The main objective of this work is to perform an exhaustive evaluation of sperm quality from Senegalese sole F1 males exposed to different hormonal treatments.Peer reviewe

SOLE FARMING: There or thereabouts!

After years of uncertainty, it is a pleasure to report that sole is now being commercially farmed in significant quantities in Europe! Even though production levels are modest compared with other well-established species and there is still a considerable amount to be done to underpin the further development of the industry, a significant increase in production did provide positive cause for optimism at the latest Workshop on the Cultivation of Soles. The fifth Workshop in a series which began in 2002 was held from 5-7 April 2011 and was again hosted by CCMAR, University of the Algarve, Faro, Portugal where we were able to benefit from their excellent facilities and organizational support. An account of the previous Workshop was published in this journal (vol. 34/1). Despite the recent severe financial pressures, the level of interest in this Workshop was high with 75 registered participants. As the countries with the greatest involvement in the field Spain & Portugal contributed a large majority (86%) of these. The rest were from Norway, The Netherlands, Italy, UK and France, another country where significant production facilities are being developed. About a third of the participants were from industry, reflecting the present high level of commercial interest. This included almost all current producers, as well as many actively contemplating entering the field, and those involved in support industries such as feed and pharmaceutical companies. As previously, the Workshop sought to review the current status of the industry and, through discussions informed by presentations of current research, to identify viable options for alleviating current constraints. Thus, about one third of the Workshop was dedicated to formal presentations, the remainder to open discussion. The presentations provided clear evidence of the quality and diversity of research that is being undertaken in support of this embryonic industry. Encouragingly, a large proportion of the presentations were delivered by young post-graduate students or postdocs, providing tangible evidence of a new generation of innovative scientists entering the field!.Peer Reviewe