Jose Pedro Andrade

• PhD
• Universidade do Algarve at University of Algarve

This experiment aimed to determine the temperature limits beyond which seahorse growth and reproduction become suboptimal due to climate change. Four temperatures (16, 20, 24, and 28 °C) were tested to evaluate their effect on juvenile (1–56 days post-parturition (DPP)) and adult (one year old) long-snout seahorses, Hippocampus guttulatus. Addition...

This study investigated the effect of partially replacing fish meal with krill and copepod meals in inert diets co-fed with shrimp on the growth and nutrient digestibility of long-snout seahorses (Hippocampus guttulatus). A control diet (Diet 1) using raw starch and four experimental diets with similar protein (≈44.8%) and energy (≈15.1 MJ/kg) leve...

The mantle muscle of common cuttlefish, Sepia officinalis , is responsible both for high‐magnitude and rapid movements for locomotion, as well as sustained ventilation, which require specific metabolic, electrophysiological, and structural organization. Young cuttlefish have a highly oxidative phenotype and a rapid growth rate. Here, we show high r...

This study investigated the effect of partially replacing fish meal with krill and copepod meals in inert diets, co-fed with shrimp, on the growth and nutrient digestibility of long-snout seahorse (Hippocampus guttulatus). A control diet (Diet 1) using raw starch and four experimental diets with similar protein (≈44.8%) and energy (≈15.1 MJ/kg) lev...

This experiment aimed to determine the temperature limits beyond which seahorse growth and reproduction become suboptimal due to climate change. Four temperatures (16, 20, 24, and 28°C) were tested to evaluate their effect on juvenile (1-56 days post-parturition (DPP)) and adult (one year old) seahorses. Additionally, the reproductive performance o...

This study aimed to determine a nutritionally adequate feeding protocol for Hippocampus hippocampus juveniles. In the experimental trial, seahorses were fed copepods from 0–7 days post-parturition (DPP) and, from 8–28 DPP, four different dietary treatments: (copepods (control diet) (Cop); microalgae-enriched Artemia with a docosahexaenoic acid (DHA...

This study aimed to determine a nutritionally adequate feeding protocol for Hippocampus hippocampus juveniles. In the experimental trial, seahorses were fed copepods from 0-7 days post-parturition (DPP) and, from 8-28 DPP, four dietary treatments: (copepods (control diet), microalgae-enriched Artemia with a DHA/EPA ratio of 2:1, microalgae-enriched...

Evaluating the impacts of anthropogenic activities on Arctic wildlife is a key issue in current management and conservation strategies. With global climate change, expanding shipping routes, and increasing industrial development in the Arctic, the polar bear (Ursus maritimus) faces new challenges to its survival. Polar bear behavioral response to v...

Genetic diversity is the raw foundation for evolutionary potential. When genetic diversity is significantly reduced, the risk of extinction is heightened considerably. The long-snouted seahorse ( Hippocampus guttulatus ) is one of two seahorse species occurring in the North-East Atlantic. The population living in the Ria Formosa (South Portugal) de...

Photo-identification has been proven to be a successful individual recognition tool in seahorse species (e.g., long-snout seahorse Hippocampus reidi (Ginsburg, 1933) and long-snouted seahorse Hippocam-pus guttulatus (Cuvier, 1829)). Its use was deemed valuable for the assessment of wild populations and to understand variations in abundance over tim...

To move forward in the farming of Octopus vulgaris paralarvae, it is necessary to search for a live prey easy to obtain and maintain in the laboratory that meets the nutritional requirements of the octopus paralarvae and adapts to its predatory behaviour. Grapsus adscensionis zoeae (Crustacea, Decapoda) seems to fulfil most of these targets, and it...

Cephalopods are gaining momentum as an alternate group for aquaculture species diversification, not only because they are a good food source (highly appreciated in some worldwide markets) but they also have the potential to quickly reach a market size. However, there are some bottlenecks impeding the transition of culture technology from the labora...

Icebreaker vessels are important scientific tools, enabling access and research within the polar regions of the world, including the High Arctic. These vessels have the potential to overlap with marine mammal habitats in infrequently studied areas. Marine mammal behavioral responses to icebreaker vessel presence and distance at which responses occu...

Young juvenile cuttlefish (Sepia officinalis) can grow at rates as high as 12% body weight per day. How the metabolic demands of such a massive growth rate impacts muscle performance that competes for ATP is unknown. Here, we integrate aspects of contractility, protein synthesis, and energy metabolism in mantle of specimens weighing 1.1 g to lend i...

• This study evaluated the effects of underwater noise as a source of acoustic stress in the wild populations of Hippocampus guttulatus in the Ria Formosa, south Portugal. Two different scenarios of underwater noise were tested: transient motor boat sound (63.4–127.6 dB) and constant sound produced by the motor of the boat directly above the animal...

Examining genetic diversity, population structure, and geographic distribution has become an important part in the conservation strategies of endangered populations. However, these studies rely on tissue samples collection for DNA analysis which may be problematic for species with a sensitive conservation status. Partial fin-clipping has been emplo...

The aim of the present study was to determine the effect of Artemia metanauplii endogenous fatty acid (FA) metabolism in the actual availability of dietary essential fatty acids (EFA) for Octopus vulgaris paralarvae development. To this end, both Artemia metanauplii inherent radiolabelled FA metabolism and the Octopus vulgaris paralarvae FA metabol...

Recent findings reported a significant decrease in abundance of two seahorse species (Hippocampus guttulatus and H. hippocampus) in the Ria Formosa lagoon (South Portugal) and no direct causes have been, so far, clearly identified. This study aimed to describe fluctuations in the local seahorse populations through monthly surveys over a course of a...

To overcome the bottleneck of reproduction in cuttlefish, Sepia officinalis, aquaculture development, there is need for new tools or refinement of methods. While attaining low welfare impact on individuals, procedures to allow for in vivo individual sexual and maturity determination, tagging and collection of samples for high quality DNA are needed...

The present study compared the lipid composition and in vivo capability of Artemia sp. metanauplii (the main live prey used in aquaculture) and Grapsus adscensionis zoeae (as a wild zooplankton model) to metabolise unsaturated fatty acids. The two species were incubated in vivo with 0.3 μM of individual [1-¹⁴C]fatty acids (FA) including 18:1n-9, 18...

Since January 1st 2013 all cephalopods (Mollusca) became protected when used in research under EU Directive European Directive 2010/63/EU), following Australia, Canada and New Zealand due to a body of evidence suggesting they are capable of feeling pain, can suffer psychologically (Andrews et al., 2013) and possess cognitive abilities which may sur...

Poster presented at Aquaculture Europe 2016

The objective of the present study was to characterise the fatty acid (FA) profiles of the major phospholipids, of Octopus vulgaris and Sepia officinalis hatchlings, namely phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PI) and phosphatidylethanolamine (PE); and to evaluate the capability of both cephalopod species on diet...

This work tested the effect of using different live and frozen feed on the growth performance of Syngnathus typhle. It was divided into two experiments. In Experiment I Artemia and Atlantic ditch shrimp (Palaemonetes varians) larvae were used as live diets, whilst in Experiment II frozen mysids Mesopodopsis slabberi and frozen P. varians were used....

The deployment of Artificial Holdfast Units (AHU) has been demonstrated as an effective tool for creating holdfast and sheltering conditions for Hippocampus guttulatusin the Ria Formosa (South Portugal). Preliminary results obtained with a pilot-scale AHU showed a high settlement rate, with recorded densities of up to 13.1 individuals.m-2. With the...

The deployment of Artificial Holdfast Units (AHU) has been demonstrated as an effective tool for creating holdfast and sheltering conditions for Hippocampus guttulatus in the Ria Formosa (South Portugal). Preliminary results obtained with a pilot-scale AHU showed a high settlement rate, with recorded densities of up to 13.1 individuals.m ⁻² . With...

Identifying sources of marine population variability is a central goal in marine ecology and conservation, which requires long-term, repeated monitoring to assess whether there is cause for concern, particularly for species with vulnerable life history traits. Between 2001 and 2009 there were substantial declines in populations of two seahorse spec...

The deployment of Artificial Holdfast Units (AHU) has been demonstrated as an effective tool for creating holdfast and sheltering conditions for Hippocampus guttulatus in the Ria Formosa (South Portugal). Preliminary results obtained with a pilot-scale AHU showed a high settlement rate, with recorded densities of up to 13.1 individuals.m-2. With th...

A significant decline in the seahorse populations in the Ria Formosa (south Portugal) was recently reported and holdfast availability suggested as a particularly important variable that influences the abundance of the long-snouted seahorse Hippocampus guttulatus and the short-snouted seahorse H. hippocampus. In order to test the usefulness of artif...

This study investigated the effect of dietary astaxanthin supplementation on egg quality and juvenile growth of long snout seahorse (Hippocampus guttulatus). Captive breed seahorse broodstock were fed four diets composed of frozen shrimp [Atlantic ditch shrimp, Palaemonetes varians) used as a vector to deliver artificial diets with increasing level...

In this study, two new alternative preys: Grapsus adscensionis zoeae (as sole prey) and Palaemon elegans zoeae (in cofeeding with Artemia sp.), as well as, Artemia sp. juveniles were used as feed for octopus paralarvae, as a way to understand its lipid requirements. Total lipid (TL) content, lipid class (LC) and fatty acid (FA) profiles of preys, o...

Comparisons of three sets of surveys in the Ria Formosa Lagoon, Portugal, over a 13 year period (2001-2002, 2008-2009 and 2010-2013) revealed significant population fluctuations in at least one of the two seahorse (Hippocampinae) species living there, and that those fluctuations were potentially associated with habitat changes in the lagoon. After...

Cuttlebone, the sophisticated buoyancy device of cuttlefish, is made of extensive superposed chambers that have a complex internal arrangement of calcified pillars and organic membranes. It has not been clear how this structure is assembled. We find that the membranes result from a myriad of minor membranes initially filling the whole chamber, made...

Identifying sources of marine population variability is a central goal in marine ecology and conservation, which requires long-term, repeated monitoring to assess whether there is cause for concern, particularly for species with vulnerable life history traits. Between 2001 and 2009 there were substantial declines in populations of two seahorse spec...

Two different Underwater Visual Census (UVC1 and UVC2) were performed at three sites in the Ria Formosa, using 30 meter transect belts, and compared for differences in seahorse density and holdfast availability. Each UVC differed in transect placement and total survey area coverage. The observed Hippocampus guttulatus density was significantly high...

A significant decline in the seahorse populations in the Ria Formosa has been recently reported and holdfast availability suggested as a particularly important variable that influences the abundance of the long-snouted seahorse (Hippocampus guttulatus) and the short-snouted seahorse (H. hippocampus). In order to test the usefulness of artificial ho...

Since January 2013, cephalopods are protect by specific legislation regarding welfare under experimental conditions. In addition, due to specificity of their biology, there is need for development or refinement of existing tools that will contribute to a better assessment of reproduction in captivity. For instance, despite the importance of tempera...

A recent revival in using cephalopods as experimental animals has rekindled interest in their biology and life cycles, information with direct applications also in the rapidly growing ornamental aquarium species trade and in commercial aquaculture production for human consumption. Cephalopods have high rates of growth and food conversion, which for...

In this study, the spot pattern in Hippocampus guttulatus was analysed using a computer programme algorithm that allowed individual comparison. This methodology was first tested in a controlled environment using 51 adult and 55 juvenile H. guttulatus. Positive matches were obtained in 86·3 and 83·6% of the adults and juveniles, respectively. In a s...

a b s t r a c t The common octopus (Octopus vulgaris), a promising species for aquaculture, spawns easily under cap-tivity from mature females (usually above 1 kg wet weight). Octopus juveniles and adults are collected from nature to obtain eggs and paralarvae for aquaculture development trials. In July 2011, a very small female (150 g wet weight b...

This chapter reviews the importance of the European cuttlefish, Sepia officinalis, as a potential species for aquaculture and its applications. It provides an overview of cuttlefish culture, its current state of art and future trends. Present cuttlefish culture-related research and recently developed technologies are described. This includes a desc...

Since 1999, CCMAR has been researching technology for the development of the European cuttlefish, Sepia officinalis, aquaculture and considering the best welfare practice. This species is seen as a very interesting animal model, with application in neuroscience, behavior, evolution, or even climate change. It is also an aquaculture diversification...

This study was carried out to estimate lysine, methionine and arginine dietary requirements of juvenile Atlantic ditch shrimp, Palaemonetes varians. Three series of five isoproteic and isoenergetic diets [45% crude protein (CP), 14.7 MJ digestible energy (DE)/kg] were formulated to contain increasing levels of either lysine (1.2–2.8 g/100 g of diet...

In order to determine the in vivo capability of Octopus vulgaris hatchlings to incorporate and esterify unsaturated fatty acids (FA), hatchlings were incubated in flat-bottom 6-well tissue culture plates at a density of 90 hatchlings/well in 10 ml of seawater (36‰). Incubations (n=4) were performed with gentle stirring at 21ºC for 6 h, with 0.2 µCi...

Ontogenetic development of the digestive tract and associated organs in long snout seahorse Hippocampus guttulatus juveniles was morphologically and histologically examined from the time of release from the male's pouch until 72 h after the first meal. When released from the male's pouch, juvenile seahorses are small adult replicates. This means th...

This in vivo study shows that esterification pattern of radiolabeled ARA, EPA and DHA, into the different lipid classes of Octopus vulgaris hatchlings and Artemia sp. nauplii, is highly different, with a greater specificity in octopus for esterification of DHA into phosphatidylcholine and EPA and ARA into phosphatidylethanolamine. This fact should...

Artemia sp. is widely used in fish culture and has been used in octopus paralarval culture. However, it lacks n-3 long-chain polyunsaturated fatty acids (LC-PUFA), which are essential for marine organisms. Therefore, lipid enrichment is performed to improve Artemia lipid profile. This study determined the “in vivo” capability of Artemia nauplii to...

The effects of three light intensities (100, 350 and 1200 lux) on cuttlefish hatchling rearing performance was studied in black tanks. A total of 270 cuttlefish with a mean wet weight (MWW) of 0.089 ± 0.012 g were used in the experiment, which was undertaken during the first 50 days after hatching (hatchling stage plus the transition to the juvenil...

The common octopus (Octopus vulgaris), a promising species for aquaculture, spawns easily under captivity from mature females (usually above 1 kg wet weight). Octopus juveniles and adults are collected from nature to obtain eggs and paralarvae for aquaculture development trials. In July 2011, a very small female (150 g wet weight but with an age es...

Beaks have been used for ageing cephalopods, mainly in octopods where statoliths are not suitable for ageing. Recently it has been validated the daily deposition of beak increments in Octopus vulgaris (Cuvier, 1797) both, in the internal lateral wall surfaces (LWS) (Canali et al., 2011; Perales-Raya et al., under review) and also in the rostrum sag...

This review intends to provide a reflection regarding Directive 2010 ⁄ 63 ⁄ EU, on animal welfare, and its application concerning cephalopod breeding and experimentation in aquaculture research. To do so, we gathered different perspectives of our group members, involving two cephalopod aquaculture researchers, an aquaculture fish production technic...

The replacement of the Directive 86/609/EEC on animal welfare by Directive 2010/63/EU has reinforced the 3 R’s policy (Replacement of animals by alternatives, Reduction of number of animals and Refinement of procedures and experimental design). Also, the new Directive includes life cephalopods because they presumably are highly specialized molluscs...

According to the Water Framework Directive (WFD) transitional waters should be differentiated according to type and, in some cases, divided into different water bodies. This raises a dilemma in trying to define parts of a continuum. In the sequence of WFD several indices have been proposed including the Estuarine Fish Assessment Index, which can be...

The replacement of the Directive 86/609/EEC on animal welfare by Directive 2010/63/EU has reinforced the 3 R’s policy (Replacement of animals by alternatives, Reduction of number of animals and Refinement of procedures and experimental design). Also, the new Directive includes life cephalopods because they presumably are highly specialized molluscs...

The reproduction of the European cuttlefish (Sepia officinalis) in captivity is a technological bottleneck that might be solved through an improved understanding of cuttlefish social behaviours. Such knowledge requires behavioural observations in captivity wherein each cuttlefish can be easily recognised by the observer. However, few techniques are...

The assessment of water quality has changed markedly worldwide over the last years, especially in Europe due to the implementation of the Water Framework Directive. Fish was considered a key-element in this context and several fish-based multi-metric indices have been proposed. In this study, we propose a multi- metric index, the Estuarine Fish Ass...

The suitability of early weaning cuttlefish using frozen grass shrimp, and its effects on growth and mortality was determined in a 50-day experiment. Three food groups were used. One group (C) was fed with live prey until 25th DAH and weaned with frozen prey until the end of the experiment. In the other two groups, weaning started at the fifth DAH...

The objective of this research was to determine the effects of using tanks with different bottom areas/volumes on the growth and reproduction of the European cuttlefish, Sepia officinalis. One hundred and eighty-four juvenile cuttlefish (46.1 ± 20.9 g) were used to test replicates of 9000 L (6.67 m 2), 750 L (1.54 m 2) and 250 L (0.79 m 2 – control...

The anadromous twaite shad, Alosa fallax fallax (Lacépède, 1803), is a European Union Berne Convention Natura 2000 species, requiring protection from range states. In Portugal it is classified as "Vulnerable" by the Instituto de Conservação da Natureza using IUCN criteria but still migrates upriver to spawn in several rivers, e.g. River Mira. Evide...

Red rock crabs (Grapsus adscensionis) were collected along the coast of Tenerife (Canary Islands, Spain) throughout the sampling period, June 2010-May 2011, to investigate the breeding cycle and reproductive biology of this species. Sex ratio varied throughout the study period. The proportion of females raised during the spawning period, when the m...

The aim of this study was to determine suitable Artemia enrichment and feeding protocols for the rearing of juvenile long snout seahorse, Hippocampus guttulatus from birth. The first phase of the project, examined the effect of two different Artemia enrichments treatments (DHA-Selco®, and Chlorella sp.) on the growth performance and survival of ear...

Changes in seahorse numbers have commonly been ascribed to overfishing but other forms of human impact may be important, too. We here examine population dynamics of two species of seahorse (Hippocampus guttulatus and Hippocampus hippocampus) in a Portuguese lagoon system where there are no targeted fisheries. As part of long term research on seahor...

Recently, some of the species characteristics also point to an eventual use in cancer research. Until now, we have been following a multidisciplinary approach to develop culture methods based on knowledge regarding the species biology and ecology, which has proven to be successful. At this point, we are able to culture up to 6 consecutive cuttlefis...

This paper aimed to characterize the ichthyofauna in the estuary of the Itajai-Acu river, Santa Catarina, Brazil (26o 52' - 26o 55' S and 48o 37' - 48o 41' W) where four sampling stations were established, from September 1995 to August 1996. Fish were caught with drop nets, a 3 sided beach seine and a bottom net. Total of 2217 individuals belonging...

The effects of different tank colours (white, yellow sandy and black) on the growth, mortality and biomass production were studied for hatchling and early juvenile cuttlefish. For hatchlings, the use of different colour tanks did not promote differences in growth due to the higher variability (standard deviation) found in the white- and sand-colour...

The aim of this study was to determine the nutritional value of adult commercial cuttlefish, to develop a Quality Index Method (QIM) scheme, and to evaluate the application of some biochemical methods commonly used for freshness assessment of fish under ice storage. Additionally, shelf-life was to be determined based on both QIM and suitable bioche...

This investigation examined the effects of temperature, density and early weaning on the survival and growth of Palaemonetes varians larvae. Survival of larvae raised at 17.5 °C was not significantly different (average + standard deviation) (94 ± 5%) from the survival of those raised at 19.5 °C (95 ± 5%) and at 21.5 °C (94 ± 4%). However, the durat...

The effects of feeding three natural frozen diets, grass shrimp (Palaemonetes sp.), crayfish (Procambarus clarkii) and fish (Sardina pilchardus) and two semi-humid artificial diets (based on fish or shrimp powder) to the cuttlefish, Sepia officinalis, were analysed. Growth rate and feeding rate [FR; % body weight (BW) day−1] and food conversions (F...

The present work reports a characterization of mean wet weight and moisture, the lipid class and fatty acid (FA) composition from the total lipids (TL), of both culture and wild eggs of the cuttlefish, Sepia officinalis, throughout the embryonic development. Additionally, reproductive data, such as the number of spawnings, number and mean weight of...

Variações Inter-anuais E Entre Colónias Na Dieta E Ecologia Alimentar De Adultos E Filhotes De Chilreta Em Portugal Neste trabalho foi estudada a dieta e ecologia alimentar de adultos e filhotes de Sterna albifrons no norte e no sul de Portugal, entre 2000 e 2004, a partir de egagrópilas e presas caídas perto dos ninhos. Foram comparadas as dietas...

This investigation compared the effects of using two binders of no nutritional value, lignosol and agar, and the binding method, microbinding and microcoating, on the growth of juvenile Atlantic ditch shrimp, Palaemonetes varians, and rockpool prawn, Palaemon elegans. Shrimp were fed one basal diet which varied solely in binder type and method of i...

The anadromous Twaite shad Alosa fallax fallax (Lacépède, 1803) is globally classified as “Data Deficient” by the IUCN but the Instituto de Conservação da Natureza, Portugal, classified the species as “Vulnerable”. In this study, the aims were to describe the putative diel, seasonal and inter-annual patterns of distribution and abundance of Twaite...

Abstract –  In this work we aim to study: (i) the diel and seasonal changes in nutritional condition, herein RNA/DNA ratios, of twaite shad (Alosa fallax fallax) larvae and (ii) the influence of environmental and biological covariates on those changes. Samples were collected in the River Mira (Portugal) from February 1998 to July 2000. The RNA/DNA...

Individual growth rates, feeding rates (%BWd−1) and food conversions for cuttlefish (S. officinalis) hatchlings and juveniles were determined during this study. A flow-through system was used. Water temperature reached 30 °C during the hottest part of the day, gradually decreasing to 25 °C during the night; salinity varied between 37 ± 3 ppt and li...

This investigation examined the effect of using three different natural frozen diets; shrimp (Palaemonetes varians), mysids (Mesopodopsis slabberi) and adult Artemia on the fitness condition of adult long snout seahorse (Hippocampus guttulatus). At the end of the 12 week experimentation, significant differences on the final wet weight were found be...

Spider crab (Maja squinado) is a species of high commercial interest. It inhabits the Northeast Atlantic (Kergariou 1984; Le Foll 1993) and Mediterranean Sea and its market is based solely on captures from the wild. Its production in captivity would be a step towards the diversification of aquaculture products and the protection of natural stocks....

This investigation examined the effect of prey condition on the growth and survival of juvenile cuttlefish (Sepia officinalis). In the first group, cuttlefish were fed with daily captured live Palaeomonetes varians from the wild [daily prey (DP)], the second group was fed 5 days stocked and starved P. varians [starved prey (SP)], while in the third...

Abstract This investigation examined the effects of live prey availability on growth and survival of Sepia officinalis. Two independent experiments, comprising two feed rations each, were performed, using adequate prey size. In the first experiment, cuttlefish hatchlings were fed live mysids, Paramysis nouvelli [(feed ratio I (fr I)], at 15% body w...

The effects of feeding three natural frozen diets, grass shrimp (Palaemonetes sp.), crayfish (Procambarus clarkii) and fish (Sardina pilchardus) and two semi-humid artificial diets (based on fish powder) to mature cuttlefish, Sepia officinalis, were analysed. Growth and feeding rates (GR and FR, % BWday−1), food conversions (FC, %), and total prote...

The life cycle of cuttlefish fed ad libitum exclusively on live grass shrimp (Palaemonetes varians) was studied during 5 consecutive generations. Different culture temperatures promoted different (P<0.05) exponential growth for each life cycle, being summer generations shorter than those of winter. Higher temperatures promoted higher IGR’s and mort...

In the present study, cuttlefish (Sepia officinalis) aged 60-day-old (age-group I) and 120-day-old (age-group II) were fed with live shrimp and live fish fry for 60 days, in order to study the diet influence on growth, mantle lipid composition, and astaxanthin content in the skin. The most noteworthy difference was the higher growth observed in shr...

The present article provides an overview of cuttlefish culture, its current state of art, and future trends. Present cuttlefish culture related research, recently developed technologies (like culture systems, maternity/nursery and juve-nile and adult proceedings) are described. Finally, current problems and prospects for future research are discuss...

We used pellets and prey dropped near nests to study the diet and feeding ecology of Little Tern (Sterna albifrons) adults and chicks in northern and southern Portugal during 2000–2004. We compared diets among study areas, years, and birds breeding in two main habitat types: sandy beaches and salinas (man-made salt-pans). We also sampled prey fish...

The effects of artificial diets on growth and body condition of adult cuttlefish, Sepia officinalis were tested in two experiments. Supplemented prepared diets (fish myofibrillar protein concentrate) were fed during a 30-day and a 21-day experiments. Growth, feeding rate and food conversion of group-reared cuttlefish were analyzed. The first of the...

Fresh fish obtained from commercial landings in the harbours of Olhão and Quarteira (south Portugal) in 1998 and 1999, were examined in order to study different aspects of the reproductive biology of Microchirus azevia (Risso, 1810): spawning season, ovary maturation, length/age at first maturity and sex ratio. A five-stage maturity scale, based on...

Fresh fish obtained from commercial landings in the harbours of Olhão and Quarteira (south Portugal) in 1998 and 1999, were examined in order to study different aspects of the reproductive biology of Microchirus azevia (Risso, 1810): spawning season, ovary maturation, length/age at first maturity and sex ratio. A five-stage maturity scale, based on...

The effects of culture density on growth and broodstock management of the cuttlefish S. officinalis were studied. Cuttlefish used were one month old at the start of the experiment, on average; two densities were used (16 and 76 cuttlefish m⁻²). During the first experiment (until day 43), dead cuttlefish were replaced by individuals of similar weigh...