Thermohaline measurements in the continental shelf zone of the NW Iberian Peninsula, 1994–2006

Gago, Jesús; Cabanas, José Manuel Oro; Casas, Gerardo; Miranda, A.

doi:10.3354/cr00943

Cited by 16 publications

(6 citation statements)

References 27 publications

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“…Unfortunately, the limited number of otoliths sampled per month prevented the investigation of seasonal changes in the age-otolith diameter relationship presented here for sardine. Nevertheless, we do not expect important biases since the majority of otoliths were sampled during a relatively short period of time (~4-5 months), mostly during summer when local environmental conditions do not change dramatically (Gago et al 2011).…”

Section: Discussionmentioning

confidence: 99%

Predicting the age of sardine juveniles (Sardina pilchardus) from otolith and fish morphometric characteristics

2015

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Summary: An age prediction model based on individual morphometric characteristics (total length; weight) and otolith morphometric characteristics (diameter; weight) was investigated for juvenile sardine, Sardina pilchardus (Walbaum, 1792). Juveniles were collected from northern Portugal between May 2004 and January 2005. Daily growth rings were counted on the otoliths of 114 juveniles of 7-16 cm total length. The sample was divided into a training sample used to develop the age prediction model and a test sample used to evaluate the predictive ability of the model. The best model for predicting the logarithm of age was a linear regression with otolith diameter. The prediction of daily age was more accurate for younger (<200 days) juveniles. Overall, ages predicted from the model were unbiased in relation to ages determined from otolith microincrement counts. Moreover, predicted daily ages reproduced the overall shape of the observed age distribution and provided comparable growth estimates (0.041 cm day -1 ). The back-calculated birthdate period ranged from 29 September 2003 to 22 July 2004, with a peak in January 2004, which is consistent with the spawning season. The model presented here could be used as a method for increasing the volume of juvenile daily age data. Since growth and survival varies spatially and temporally, relationships between age and otolith/fish morphometry should not be extrapolated outside sampled periods, areas and fish size/age.

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Section: Discussionmentioning

confidence: 99%

Predicting the age of sardine juveniles (Sardina pilchardus) from otolith and fish morphometric characteristics

2015

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“…The larvae of M . brachydactyla in captivity can tolerate a temperature range similar to the measured in the coastal waters of the NW Iberian Peninsula (Gago, Cabanas, Casas, & Miranda, ). Similar trends occur in other species that inhabit cold to temperate waters (e.g., Hyas araneus : 6–12°C, Anger, ; Metacarcinus magister : ~10°C, Reed, ; Sulkin & McKeen, ; Cancer irroratus : 15–24°C, Johns, ).…”

Section: Discussionmentioning

confidence: 67%

Influence of temperature and light regime on the larval development of the common spider crab Maja brachydactyla Balss , 1922 (Brachyura: Majidae)

et al. 2018

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Temperature and light are important factors affecting production in the aquaculture industry, as they can drive behaviour and physiological responses of free-swimming larval stages. However, the influence of light on crustacean farming has received little consideration. The common spider crab Maja brachydactyla Balss, 1922 has a great potential for aquaculture because of the easy maintenance, high fecundity, and short larval development. In order to optimize larval culture techniques, we quantified the influence of temperature and light on larval survival, development, and elemental (carbon and nitrogen) body composition. Constant darkness resulted in longer developmental time as compared with daily light photoperiod (6-16 light hours). Larvae reared under constant darkness showed also reduced dry mass, carbon and nitrogen content, and C:N ratio. We also found carry-over effects of light conditions: constant darkness experienced during the zoeal stage led to increased developmental time in the megalopa stage. Temperature and light showed additive effects. We optimized the larval culture of M. brachydactyla requiring around 14 days from hatch to first juvenile by keeping cultures under 21 ± 1°C and light sources simulating the daily light cycle.

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“…ic index of females peaks in June (Regueira et al 2013), indicates that the period between maturity peak and egg hatching is about six months. Considering that embryonic development at 16°C takes about 110 days in this species (Mangold et al 1971) and since sea bottom temperature on the northwestern Iberian continental shelf ranges between 11°C and 14°C (Gago et al 2011), this longer time period should be expected. Experiments in culture indicate that females of E. cirrhosa may copulate several weeks before egg laying begins and can preserve sperm for up to six weeks (Mangold et al 1971).…”

Section: Discussionmentioning

confidence: 96%

Determination of age and growth of the horned octopus Eledone cirrhosa (Cephalopoda: Octopoda) using stylet increment analysis

Regueira

González

2015

Sci. Mar.

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Summary: Age and growth of the horned octopus Eledone cirrhosa are estimated for the first time by stylet increment analysis. Specimens were collected between March 2009 and March 2010 from the commercial trawl fishery operating off northwestern Iberian coasts. A pool of stylets representing all size classes were defined by means of modal progression analysis performed separately for each sex in northern and western fishing grounds over a total of 2220 individuals (306 males and 595 females from the northern fishing ground; and 379 males and 940 females from the western fishing ground). In total, 122 stylets belonging to individuals with a total weight ranging from 67 to 950 g were successfully analysed. Age of the specimens was estimated assuming a daily deposition rate of growth increments within the stylet. Estimated age of the specimens varied from 106 to 516 days. Differential longevity between sexes was observed, with females reaching a life span of 17 months while males attained reached only 14 months, although the possibility that this difference might be even greater is discussed. Based on estimated age, hatching date was back-calculated and it was concluded that hatching occurs throughout the year, with a peak in winter. Relative instantaneous growth rates estimated for 90-day age classes, ranged from 0.03% to 2.17% of body weight per day, depending on age. The results obtained are compared with the information available on this species.Keywords: Eledone cirrhosa; stylet increment analysis; age; life span; growth; NW Iberian Peninsula.Determinación de la edad y el crecimiento del pulpo blanco Eledone cirrhosa (Cephalopoda: Octopoda) mediante el análisis de incrementos en el estilete Resumen: La edad y el crecimiento del pulpo blanco Eledone cirrhosa son estimados por primera vez mediante el análisis de incrementos del estilete (SIA). Los especímenes fueron obtenidos, entre marzo de 2009 y marzo de 2010, provenientes de la pesquería de arrastre comercial que opera en la costa noroeste de la Península Ibérica. Un conjunto de estiletes, en representación de todas las clases de tamaño, fue definido mediante un análisis de progresión modal realizado por separado para cada sexo en los caladeros del norte y oeste, sobre un total de 2220 individuos (306 machos y 595 hembras procedentes de la costa norte y 379 machos y 940 hembras de la costa oeste). Un total de 122 estiletes, pertenecientes a especímenes con un peso total de entre 67 y 950 g, fueron analizados con éxito. La edad de los especímenes se calculó asumiendo una tasa de deposición diaria de los incrementos de crecimiento en el estilete. La edad estimada de los especímenes fue de entre 106 y 516 días. Se observó una longevidad diferencial entre sexos; en las hembras se registró una esperanza de vida de hasta 17 meses, mientras que los machos tan sólo alcanzaron 14 meses, aunque se discute la posibilidad de que esta diferencia podría ser aún mayor. En base en la edad estimada se calculó la fecha de eclosión, concluyendo que la eclosión se produce duran...

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Thermohaline measurements in the continental shelf zone of the NW Iberian Peninsula, 1994–2006

Cited by 16 publications

References 27 publications

Predicting the age of sardine juveniles (<em>Sardina pilchardus</em>) from otolith and fish morphometric characteristics

Predicting the age of sardine juveniles (<em>Sardina pilchardus</em>) from otolith and fish morphometric characteristics

Influence of temperature and light regime on the larval development of the common spider crab Maja brachydactyla Balss , 1922 (Brachyura: Majidae)

Determination of age and growth of the horned octopus <em>Eledone cirrhosa</em> (Cephalopoda: Octopoda) using stylet increment analysis

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