First Report of a Toxic Nodularia spumigena (Nostocales/Cyanobacteria) Bloom in Sub-Tropical Australia. II. Bioaccumulation of Nodularin in Isolated Populations of Mullet (Mugilidae)

Fish collected after a mass mortality at an artificial lake in south-east Queensland, Australia, were examined for the presence of nodularin as the lake had earlier been affected by a Nodularia bloom. Methanol extracts of muscle, liver, peritoneal and stomach contents were analysed by HPLC and tandem mass spectrometry; histological examination was conducted on livers from captured mullet. Livers of sea mullet (Mugil cephalus) involved in the fish kill contained high concentrations of nodularin (median 43.6 mg/kg, range 40.8-47.8 mg/kg dry weight; n = 3) and the toxin was also present in muscle tissue (median 44.0 mu g/kg, range 32.3-56.8 mu g/kg dry weight). Livers of fish occupying higher trophic levels accumulated much lower concentrations. Mullet captured from the lake 10 months later were also found to have high hepatic nodularin levels. DNA sequencing of mullet specimens revealed two species inhabiting the study lake: M. cephalus and an unidentified mugilid. The two mullet species appear to differ in their exposure and/or uptake of nodularin, with M. cephalus demonstrating higher tissue concentrations. The feeding ecology of mullet would appear to explain the unusual capacity of these fish to concentrate nodularin in their livers; these findings may have public health implications for mullet fisheries and aquaculture production where toxic cyanobacteria blooms affect source waters. This report incorporates a systematic review of the literature on nodularin measured in edible fish, shellfish and crustaceans.

Aquaculture Asia, Vol.13, No.4, pp.1-51, October-December 2008

Editorial An increasingly secure future for wastewater-fed aquaculture in Kolkata, India? by Peter Edwards. First culture-based fisheries growth cycle in Lao PDR is overwhelmingly encouraging, by Sena De Silva. Revival of abandoned shrimp farms in Krishna District of Andhra Pradesh, by National Centre for Sustainable Aquaculture (NaCSA). Growth of forward and backward industries linked with aquaculture in Kolleru Lake area, Andhra Pradesh, India, by A. K. Roy, G. S. Saha, P. Kumaraiah and N. Sarangi Effective marketing strategies for economic viability of prawn farming in Kuttanad, India, by Ranjeet K. and B. Madhusoodana Kurup. Applications of nutritional biotechnology in aquaculture, by S.D. Singh, S.K. Nayak, M. Sekar and B.K. Behera. Some technical and management aspects of catfish hatcheries in Hong Ngu district, Dong Thap province, Vietnam, by H. P. Hung, N. T. T. An, N. V. Trieu, D. T. Yen, U. Na-Nakorn, Thuy T. T. Nguyen. Nodavirus: An emerging threat to freshwater prawn farming, by Biju Sam Kamalam, J., Saravanan, S. and Ajith Stalin, J.L. Asia-Pacific Marine Finfish Aquaculture Network Magazine: Asian seabass farming: Brainstorming workshop and training in India. Comparative study for broodstock management of grey mullet (Mugil cephalus L.) in cages and earthen ponds with hormone treatment, by Nani Gopal Das, Md. Shahadat Hossain, Sushanta Bhattacharjee and Prabal Barua. Cultivation of gilthead sea bream (Sparus auratus L.) in low saline inland water of the southern part of Israel desert, by Samuel Appelbaum and A. Jesu Arockia Raj. Mariculture development opportunities in SE Sulawesi, Indonesia, by La Ode M. Aslan, Hotman Hutauruk, Armen Zulham,Irwan Effendy, Mhummaed Atid, Michael Phillips, Lars Olsen, Brendan Larkin, Sena S De Silva, Geoff Gooley. Improved hatchery and grow-out technology for marine finfish. NACA Newsletter

Hubungan panjang berat dan faktor kondisi tiga jenis ikan yang tertangkap di perairan Kuala Gigieng, Aceh Besar, Provinsi Aceh

The study of the length weight relationships and condition factors of the brackishwater fishes found in Kuala Gigieng was conducted. The objective of the present study was to evaluate the growth patterns and condition factor of the belanak (Mugil cephalus), seriding (Ambassis koopsii) and petek (Leiognathus fasciatus). The sampling was conducted for eight time on July 2011 by using gillnet and castnet. The results showed that the belanak (M. cephalus) and seriding (A. koopsii) have allometric negative growth patten, while the petek (L. fasciatus) has an allometric positive. In addition, the relative weight condition factor’s was higher than 100. And the Fulton’s condition factor were not different significantly among fishes. Indicating the condition of the Kuala Gigeng is relatively in good condition and support fish growth as well.

Fish assemblages found in tidal-creek and seagrass habitats in the Suwannee River estuary

Fish assemblages were investigated in tidal-creek and seagrass habitats in the Suwannee River estuary, Florida. A total of 91,571 fish representing 43 families were collected in monthly seine samples from January 1997 to December 1999. Tidal creeks supported greater densities of fish (3.89 fish/m2; 83% of total) than did seagrass habitats (0.93 fish/m2). We identified three distinct fish assemblages in each habitat: winter−spring, summer, and fall. Pinfish (Lagodon rhomboides), pigfish (Orthopristis chrysoptera), and syngnathids characterized seagrass assemblages, whereas spot (Leiostomus xanthurus), bay anchovy (Anchoa mitchilli), silversides (Menidia spp.), mojarras (Eucinostomus spp.), and fundulids characterized tidal-creek habitats. Important recreational and commercial species such as striped mullet (Mugil cephalus) and red drum (Sciaenops ocellatus) were found primarily in tidal creeks and were among the top 13 taxa in the fish assemblages found in the tidal-creek habitats. Tidal-creek and seagrass habitats in the Suwannee River estuary were found to support diverse fish assemblages. Seasonal patterns in occurrence, which were found to be associated with recruitment of early-life-history stages, were observed for many of the fish species.

Brevetoxin in two planktivorous fishes after exposure to Karenia brevis: implications for food-web transfer to bottlenose dolphins

Brevetoxin uptake was analyzed in 2 common planktivorous fish that are likely foodweb vectors for dolphin mortality events associated with brevetoxin-producing red tides. Fish were exposed to brevetoxin-producing Karenia brevis for 10 h under conditions previously reported to produce optimal uptake of toxin in blood after oral exposure. Striped mullet Mugil cephalus were exposed to a low dose of brevetoxin, and uptake and depuration by specific organs were evaluated over a 2 mo period. Atlantic menhaden Brevoortia tyrannus specimens were used to characterize a higher brevetoxin dose uptake into whole body components and evaluate depuration over 1 mo. We found a high uptake of toxin by menhaden, with a body to water ratio of 57 after a 10 h exposure and a slow elimination with a half life (t1/2) of 24 d. Elimination occurred rapidly from the intestine (t1/2 < 1 wk) and muscle (t1/2 ≈ 1 wk) compartments and redistributed to liver which continued to accumulate body stores of toxin for 4 wk. The accumulation and elimination characteristics of the vectoring capacity of these 2 fish species are interpreted in relation to data from the Florida Panhandle dolphin mortality event of 2004. We show that due to slow elimination rate of brevetoxin in planktivorous fish, brevetoxin-related dolphin mortality events may occur without evidence of a concurrent harmful algal bloom event.

Effect of farm made feeds on polyculture of shrimp (Penaeus monodon) and three brackishwater finfish species

A study was conducted to evaluate the effects of feed made from locally available ingredients on polyculture of shrimp and three brackishwater finfish species. Hatchery produced post-larvae (PL) of shrimp Penaeus monodon (0.005g) were stocked at the rate of 15,000 PLs/ha. Brackishwater finfish species Liza parsia, Mugil cephalus and Rhinomugil corsula of 0.63-1.4lg collected from local rivers were stocked at the rate 8,000, 1,000 and 2,000/ha, respectively in four treatments. Shrimp and finfishes were fed four different experimental diets composed of fish meal, mustard oil cake, rice bran, oyster shell power and vitamin premixes at the rate of 3-5% estimated crop/day for 195 days. Among four treatments, P. monodon showed comparative better growth in T4 and T3. Finfish L. parsia showed its better performance in treatment T2. Species M. cephalus and R. corsula showed insignificant production. P. monodon showed better growth with diet of fish meal and mustard oil cake@ 28.84 and 33.65%, respectively in T 3 and 19.22 and 43.27%, respectively in treatment T4.

Diel feeding chronology of six fish species in Anchuthengu backwater, Kerala

The study examined diel feeding chronology of six fish species in Anchuthengu backwater, Kerala. Over the 24h period, more or less same items contributed to the diet of Arius arius. Mugil cephalus exhibited substantial diel variation in diet composition, with algae forming the main dietary component in the diurnal diet, and prawns in the crepuscular and nocturnal diets. Algae and rotifers formed the main food items throughout the 24h feeding period in Hyporhamphus xanthopterus. No change was noticed in the diel diet composition in Ambassis commersonii. While Caranx ignobilis showed no diel variation, Gerrus lucidus that feeds on a variety of prey items seemed to exhibit some diel variation in feeding. All the fish examined had diurnal feeding peaks. The results indicate that because of diel variation in diet composition and feeding periodicity for these six species, dietary analysis conducted at only one interval would not provide an accurate representation of the diet of these species.

Nutritional quality of some food fish

The proximate compositions and amino acid make-up of silver jew fish (Johnius argentatus), Indian halibut (Psettodes erumei), grey mullet (Mugil cephalus) and pearl spot (Etroplus suratensis) are reported. Calorific values of these fishes have been calculated from their proximate compositions and their amino acid make-up compared with the available data for beef and egg. From the study, pearl spot is adjudged to be the most nutritive among the fishes studied, followed by Indian halibut, grey mullet and silver jew fish.

Fish farm technology. 1 - Brackishwater fish culture based on "aquafeed"

A method has been evolved to enhance the production of natural feed in brackish water fish farms by providing substrates for bio-growth ('aquafeed' production) which is a biomass complex consisting of sedentary and associated organisms of plant and animal species. The seasonal fluctuations of the aquafeed production over different substrates ranged as: 787-1830g/coconut leaf (6m²)/45 days, 16.0-072.9g/glass panel (2x10x10cm²)/30 days, 52-230g/nylon mat (2x25x25cm²)/30 days and 18.6-123.1g/wooden block (6x10x10cm²)/30 days. The average dry weight composition of the major components of aquafeed obtained in the present study was sand-silt-clay 40%, protein 22%, carbohydrate (water soluble) 1.8% and fat 3.35% (water content 85%). Mugil cephalus of 1.85 cm reared in a 0.01ha pond and fed on aquafeed attained a size of 23 cm length and 146.73g weight during one year. Survival rate was 54% at a density of 1000/ha. Salinity and temperature of the pond during the culture period ranged between 1.4 and 32.8‰ and 28.1 and 36.5°C respectively.

Synopsis of the species of Myxobolus Butschli, 1882 (Myxozoa : Myxosporea : Myxobolidae)

A synopsis of 744 nominal species of Myxobolus Butschli, 1882 (Myxozoa, Myxosporea, Myxobolidae) is presented. For each species, the relevant morphometric and morphological data are indicated, as well as the host(s), site(s) of infection within the host and type-locality.

青岛近海六种海产鱼染色体组型的比较研究

采用活体注射秋水仙碱制备鱼类肾细胞染色体、PHA肌肉注射制备肾细胞染色体和鱼类早期胚胎制备染色体等多种方法。以空气干燥法制片Giemsa染色，对鲻鱼Mugil cephalus Linnaeus、真鲷Pagrosomus major（Temminck et Schlegel）、黑鲷Sparus macrocephalus（Basilewsky）、黑鮶Sebastes schlegeli （Hilgendorf）、石鲽Kareius bicoloratus （Basilewsky）、牙鲆Paralichthys olivaceus （Temminck et Schlegel）等分属四目、五科的六种海产鱼的染色体组型进行了考察和分析。研究结果表明：1、一般活体注射秋水仙碱制备海产鱼肾细胞染色体方法的有丝分裂指数虽然略低于PHA制备肾细胞染色体方法的有丝分裂指数。但它是最快最简便且很有效的方法，利用鱼类早期胚胎制备海产鱼染色体标本的方法也很有效，但要受到生物季节的限制。2、通过对六种海产鱼染色体组型分析得到，鲻鱼为48条端部着丝点染色体；真鲷的二倍体2n=48，有1对亚端部着丝点染色体。其余全部为端部着丝点染色体；黑鲷的二倍体2n=48。有3对中部着丝点染色体。2对亚中部着丝点染色体，其余全部为端部着丝点染色体。黑鮶的二倍体2n=48，有1对中部着丝点染色体，其余全部为端部着丝点染色体，石鲽的二倍体2n=48。全部为端部着丝点染色体；牙鲆的二倍体2n=48，全部为端部着丝点染色体。本文还对鱼类染色体的多态现象以及染色与进化的关系进行了讨论。

Prevalence of Aeromonas hydrophila in fish and prawns from the seafood market of Coimbatore, South India

Five hundred and thirty six samples offishes and 278 prawn samples from the major fish market ofCoimbatore, South India, were analysed for the prevalence of Aeromonas hydrophila over a period of2 years (June 1997–May 1999). The prevalence level of A. hydrophila varied from 17.62% in prawns to 33.58% in fishes. More than 30% of the popular table fishes such as Sardinella longiceps, Rastrelliger kanagurta, Mugil cephalus and Caranx sexfasciatus were tested positive for this organism. Among the different species of the prawns analysed, Penaeus semisulcatus showed higher incidence (23.52%). Seasonal variation in the prevalence levels of A. hydrophila in fish and prawns revealed a higher prevalence during the monsoon season during 1997–98 and 1998–99. Of the different body parts of the fishes analysed for A. hydrophila, the intestinal samples showed higher prevalence (38.43%), followed by body surface (32.46%) and gill (29.10%). Considering the psychrotrophic nature and role of A. hydrophila as a pathogen ofemerging importance, the considerably high levels ofthis organism in a popular food item such as fish and prawn raises serious concern

An Estuarine Low Temperature Fish Kill in Mississippi, with Remarks on Restricted Necropsies

In January 1973, large numbers of Mugil cephalus (striped mullet), weighing approximately 250 gm each, died in two freshwater localities in tidewater bayous of Jackson County, Mississippi. Fish identified as Mugil curema, M. cephalus, Megalops atlantica, Dormitator maculatus, and Fundulus grandis were found dead in other low saline estuarine areas. Fish-kills during cold periods are less commonly encountered in Mississippi than in Texas or Florida. This particular incident is attributed to conditions of stress for fishes incompletely acclimated to the encountered low temperatures. The most deleterious stress was the low saline water which probably allowed a breakdown in the fishes' ion-osmoregulatory mechanisms. Striped mullet and other euryhaline fishes in salinities greater than 6 ppt survived, as did freshwater centrarchids and ictalurids in areas with dying mullet. Other stresses thought to contribute to the weakening of striped mullet in Paige Bayou during the period of rapidly decreasing temperatures include starvation and high levels of pesticide residues. In examined fish, the alimentary tracts were devoid of food, the gall bladders were distended and leaking bile, the livers contained excess lipid material and were often stained throughout with bile pigments, and the levels of DDT metabolites and endrin residues in the liver were higher than in control fish. Stress caused by low levels of dissolved oxygen, toxic substances in the water, or disease was discounted as a cause of death.

Posibilidades de cultivo de nuevas especies marinas en el área mediterránea

La acuicultura, el cultivo y cría de animales y plantas acuáticas, representa en la actualidad una fuente esencial de proteína animal y vegetal altamente saludable y nutritiva, proporcionando un sistema de vida y de ingresos en todo el mundo. La acuicultura además de ser un motor para el desarrollo social y económico de las áreas costeras marinas y fluviales mundiales, supone en muchas regiones subdesarrolladas una garantía de alimento de alta calidad y es clave en la seguridad alimentaria de sus poblaciones. El desarrollo de la acuicultura se ha realizado fundamentalmente en los últimos 50 años, y ha sido sobre todo en la década de los años 80, cuando la acuicultura ha experimentado un fuerte crecimiento con tasas anuales que superan el 6%. Con el estancamiento de la producción pesquera y el incremento de la población mundial, la acuicultura se presenta como la única fuente posible de suministro de proteínas (vegetales y animales) de alta calidad, ricas en aceites omega 3 (EPA y DHA) de origen acuático. En la actualidad la producción procedente de la acuicultura supera los 95 millones de toneladas anuales, siendo ligeramente superior a los 94 millones de toneladas anuales provenientes de la pesca extractiva. De este total mundial acuícola, la producción asiática representa el 89%, mientras que la europea el 4,2% Aunque el 46% de la producción mundial acuícola se concentra únicamente en solo 10 especies, una de las principales características de la acuicultura es la gran diversidad de especies cultivadas, más de 500, realizándose su cría bajo diferentes tecnologías y sistemas productivos. El ámbito de esta tesis, es únicamente la acuicultura marina que se desarrolla en las aguas del mar mediterráneo, indistintamente de los sistemas y tecnología de producción utilizados. Los principales grupos de cultivo que se realizan en las aguas del Mediterráneo son los moluscos y los peces, siendo muy escasos los cultivos de otros grupos como crustáceos y macroalgas. La piscicultura marina mediterránea está dominada por el cultivo en jaulas flotantes de dos especies, la dorada (Sparus auratus) y la lubina (Dicentrarchus labrax). Estas dos especies y tras 30 años de experiencia de cultivo, mantienen todavía una ineficiencia productiva alta (reducida selección genética, lento crecimiento hasta talla comercial, alto factor de conversón del pienso…) y además ocupan un estrecho nicho de mercado, ya que prácticamente toda la comercialización de la dorada y lubina se realiza en fresco y sin elaborar ni transformar, a una talla media de 500 g. Para dar respuesta desde la acuicultura mediterránea al alto consumo y a la creciente demanda que en la Unión Europea existe de los productos acuícolas, y en especial los productos elaborados y transformados, es necesario de manera urgente, un aumento de la producción de las especies ya cultivadas (dorada y lubina) mediante la mejora de su eficiencia productiva, al mismo tiempo que se debe iniciar la producción industrial de nuevas especies piscícolas, mediante la diversificación de los cultivos. Para llevar a cabo esta diversificación, se hace necesario el establecimiento de una metodología clara, que asegure una selección de especies apropiadas y rentables para la industria acuícola mediterránea, cuyo cultivo sostenible debiera cumplir con los desafíos que el sector tiene. Nuevas especies que complementen y cubran las demandas actuales y futuras del mercado Europeo e Internacional de productos acuícolas. Nuevas especies con parámetros productivos eficientes, que garanticen unos costes productivos competitivos. Nuevas especies que puedan ser cultivadas utilizando como base la tecnología de producción ya existente en el sector. El objetivo de esta tesis es la definición y desarrollo de una metodología sencilla para la selección de nuevas especies piscícolas marinas para su cultivo eficiente y sostenible Y bajo la aplicación de esta metodología, la selección de un grupo de especies piscícolas para su cultivo rentable a corto y medio plazo (6-8 años) en el Mediterráneo. Para ello se ha definido y aplicado una metodología con la que se han evaluado diez especies candidatas, previamente escogidas de una serie de listas previas originadas en los distintos estudios y trabajos de diversificación realizados con anterioridad por otros equipos de investigación. Estas especies candidatas han sido: Seriola dumerili. (Seriola) , Argyrosomus regius (Corvina), Polyprion americanus (Cherna), Ephinephelus marginatus (Mero), Dentex dentex (Dentón), Pagrus pagrus (Pargo), Solea senegalensis (Lenguado del Senegal), Thunnus thynnus (Atún rojo), Mugil cephalus (Lisa), Coryphaena hippurus (Lampuga). El conjunto de estas especies ocupa un amplio y variado espectro dentro de las distintas áreas de mercado, productiva, tecnológica, y medioambiental . Y en todas ellas existe una experiencia mínima en sus diferentes fases de cultivo. En el desarrollo de la metodología de selección, en esta tesis se han definido diversos parámetros de evaluación, considerados como los más significativos y sencillos de aplicar. Los parámetros se han agrupado en tres bloques, el comercial, el productivo y el medioambiental. El Bloque de Mercado, comprende aquellos criterios que están relacionados con la comercialización de la especie. Calidad de la carne del pescado. Competencia con otras especies en el mercado. Potencial de Transformado. Precio de venta del pescado. El bloque Medioambiental incluye criterios del grado de idoneidad de la especie en la región y del grado de impacto ambiental de su cultivo. Rango de temperaturas del agua óptimo para el cultivo. Potencial impacto ambiental de su cultivo. Eslabón trófico de la especie.. El bloque Productivo, engloba los criterios y parámetros relacionados con el nivel de conocimiento y control que sobre su cultivo existen ( larvario, engorde, tecnología) Grado de control de la fase larvaria. Disponibilidad de alevines en el sector Crecimiento. Factor de conversión Aprovechamiento de la capacidad productiva instalada, Coste de inversión. Previa a la evaluación se han descrito las principales características de las especies candidatas en función del estado y experiencia actual sus cultivos. En la aplicación de estos criterios se han establecido matrices de evaluación y a cada criterio se le ha asignado un valor diferente en función de sus características y propiedades selectivas. Los resultados obtenidos mediante la aplicación de la metodología de evaluación propuesta, han señalado la seriola y la corvina como especies más recomendadas para su puesta en cultivo en el Mediterráneo a corto y medio plazo. Las otras dos especies seleccionadas han sido la lisa y la lampuga. Como conclusión final podemos señalar que el cultivo de nuevas especies es fundamentalmente para el desarrollo sostenible de la acuicultura mediterránea. Esta diversificación debe basarse en la aplicación de una metodología sencilla y práctica, que garantice una selección de especies cuyo cultivo sea rentable y abarquen nuevos segmentos de mercado. ABSTRACT Aquaculture, the cultivation and breeding of aquatic animals and plants, currently represents an essential source of highly nutritious and healthy protein that provides a way of life and income all over the world. Apart from being a social and economic driver in coastal and marine areas, it also entails a guaranteed high quality nourishment in many undeveloped areas being key to the alimentary safety of their population. Aquaculture has developed mainly in the last 50 years and experienced a high growth especially during the Eighties when the annual rates were above 6%. With fishing production stagnating and the global population increasing, aquaculture emerges as the only possible animal and vegetable protein source of aquatic origin, high in quality and omega 3 oils (EPA and DHA). Here and now, aquaculture production is over 95 million tons per year, which is slightly higher than the 94 million tons per year that come from extractive fisheries. From this aquaculture total, Asiatic production represents 89% while Europe´s is only 4.2%. Even though 46% of the global aquaculture production focuses just on 10 species, one of the main characteristics of aquaculture is the wide diversity of cultivated species –over 500– using different technologies and production systems. This PhD’s scope is only marine aquaculture in Mediterranean water, regardless of the technology or systems used. The main crop groups in the Mediterranean sea are molluscs and finfish, while crustacean and macroalgae cultivations are very limited. Mediterranean fish culture is dominated by the cultivation in floating cages of two species: Bream (Sparus auratus) and Bass (Dicentrarchus labrax). After 30 years of farming, these two species still keep a high productive inefficiency –reduced genetic selection, slow growth to marketable size, high feed conversion rate– and fill a narrow niche market as practically all bream and bass is sold fresh and whole, unprocessed and untransformed, with an average size of 500 grams. To meet the high consumption and growing demand of aquaculture products, in the European Union (especially those prepared and transformed), Mediterranean aquaculture needs to urgently increase the production of the species already under cultivation (Bass and Bream) by means of improving its productive efficiency and at the same time begin initiating industrial production of new species by diversifying the cultivation. To carry out this diversification it is necessary to establish a clear methodology that ensures the selection of adapted and profitable species for the Mediterranean aquaculture industry. The sustainable farming of these new species needs to meet the challenges this sector faces: New species that complement and meet the current and future needs of the European and International markets for aquaculture products. New species with efficient production parameters that ensure competitive production costs. New species that can be cultivated using already existing production technologies. The aim of this PhD is to define and develop a simple methodology for the selection of new marine fish species for their efficient and sustainable cultivation. And by applying this methodology, to select a group of fish species for its profitable crop in the short and medium term (6-8 years) in the Mediterranean. For this, a methodology has been defined and applied evaluating ten candidate species selected from a series of lists originated from different studies and from diversification works previously conducted by other research teams. These candidate species are: Seriola dumerili. (Greater amberjack), Argyrosomus regius (Meagre), Polyprion americanus (Wreckfish), Ephinephelus marginatus (Dusky grouper), Dentex dentex (Common dentex), Pagrus pagrus (Red porgy), Solea senegalensis (Senegal sole), Thunnus thynnus (Bluefin tuna), Mugil cephalus (Grey mullet), Coryphaena hippurus (Dolphinfish). All these species occupy a broad and varied spectrum within different productive, technological and environmental market areas. There is minimal experience in their different stages of cultivation for all of them. While developing the selection methodology several evaluation parameters have been defined in this PhD, considered the most significant and simple to apply. The parameters are grouped in three blocks: commercial, productivity and environmental. Market block comprises criteria related to the marketing of the species. Quality of the fish meatCompetition with other species in the marketTransformation potentialFish selling price Environment block includes criteria related to the degree of suitability of the species in the region and the degree of environmental impact of their cultivation. Optimal water temperature range for cultivationPotential environmental impact of their cultivationTrophic chain level. Productivity block includes criteria and parameters related to the level of knowledge and control over their cultivation (larval, ongrowing, technology) Degree of control of the larval stageAvailability of alevin in the sector GrowthFeed conversion rate. Exploitation of installed capacityInvestment cost Prior to the evaluation, the main characteristics of the candidate species have been described based on the current status and experience of their cultivations. When applying these criteria evaluation matrices have been established assigning to each criteria a different value depending on their characteristics and selective properties. The results obtained by applying the proposed assessment methodology have identified the Greater Amberjack and Meagre as the most recommended species for farming in the Mediterranean in the short and medium term. The other two selected species were the Grey Mullet and the Dolphinfish. In conclusion, the cultivation of new species is crucial for the sustainable development of Mediterranean aquaculture. This diversification has to be based on the application of a simple and practical methodology that guarantees a selection of species whose cultivation is profitable and covers new market segments.

The life cycle of Paracardicoloides yamagutii Martin, 1974 (Digenea: Sanguinicolidae)

The sanguinicolids Paracardicoloides yamagutii Martin, 1974 and Plethorchis acanthus Martin, 1975 were obtained from their definitive hosts, Anguilla reinhardtii Steindachner and Mugil cephalus Linnaeus (respectively) in the tributaries of the Brisbane River, Queensland, Australia. Two putative sanguinicolid cercariae were collected from a hydrobiid gastropod, Posticobia brazieri Smith, in the same waters. The two cercariae differ markedly in size and the form of their sporocysts. Both putative cercariae develop in the digestive gland of Po. brazieri. The ITS2 rDNA region from these sanguinicolids and a Clinostomum species (utilised as an outgroup due to the close morphological similarities between the cercarial stages of the Clinostomidae and the Sanguinicolidae) were sequenced and aligned. Comparison of the ITS2 sequences showed one cercaria to be that of P. yamagutii. This is the first sanguinicolid life history determined by a molecular method. P. yamagutii is the fourth sanguinicolid known to utilise a freshwater hydrobiid gastropod as its intermediate host. ITS2 rDNA is effective in distinguishing sanguinicolids at the species level.