G. Jay Parsons

Size-related feeding and gastric evacuation measurements for the Southern brown shrimp Penaeus subtilis

Studies attempting to optimise feeding methods in penaeid aquaculture have often relied on results of growth, survival performance and food conversion ratios. At present, data relating to maximum ration, ingestion rates (IRs), faecal production rates (FPs), foregut evacuation and appetite revival are lacking for Penaeus spp. despite their relevance to the development of models aimed at maximising food use in shrimp culture systems. Size-related feeding and gastric evacuation (GE) measurements were determined for Penaeus subtilis by conducting laboratory-based feeding trials on individual animals. A total of 3482 samples of feed and (or) faeces were collected for quantitative analysis derived from 307 shrimp. Food ingestion was a function of shrimp body weight (BW). Feeding intensity increased progressively with shrimp size, but inversely in percentage terms, resulting in a larger faecal production per BW for smaller shrimp. On average, P. subtilis food ingestion was equivalent to 2.3% of its BW per hour, but consumption in shrimp with empty stomachs reached 4.9% BW/h. Foregut clearance rates (13%) peaked 3 h after food recovery, with the bulk of faeces being produced within 1 h. Food load occurred progressively as more feed was given and evacuated from shrimp stomachs, while feeding continued at reduced levels. Data indicated that control of feeding intensity and resumption of food intake by P. subtilis were not markedly affected by the level of their stomach fullness or by longer food administration intervals. The daily administration of food in shorter feeding intervals, although at continually reduced amounts, may be advantageous in the culture of P. subtilis.

Effects of the Southern brown shrimp, Penaeus subtilis, predation and artificial feeding on the population dynamics of benthic polychaetes in tropical pond enclosures

In less intensive shrimp culture systems, polychaetes are known to be a major food item of several penaeid species. Under these conditions, very little is known about their population dynamics and the possible interactions with penaeid predation and artificial feeding. This work examined the effects of Penaeus subtilis, predation, stocking density and supplemental feeding on the population dynamics of polychaetes in pond enclosures. The work was conducted in a shrimp pond, where forty-five 9-m2 open-bottom enclosures were built. The study consisted of four treatments: enclosures with feed and shrimp (i.e., FS); enclosures without feed and shrimp (NFNS, control); enclosures with shrimp and no feed (NFS); and, enclosures with feed, but no shrimp (FNS). For enclosures with shrimp, four initial shrimp stocking densities were used (i.e., 5, 10, 15 and 20 shrimp/m2). Benthic polychaetes were collected 2 days prior to shrimp stocking and were sampled every 10 days over the complete rearing cycle. A total of 1,631 substrate samples of 20.43 cm2 containing 20,283 polychaetes were collected for analysis. Overall, polychaete density and dry biomass over the production cycle varied from 956 to 11,921 polychaetes/m2 and 1.17 to 2.58 g/m2, respectively. Six polychaete families were identified and ranked relative to their numerical occurrence and frequency (Cn) as follows: (1) Spionidae (Cn=52.3%), (2) Capitellidae (Cn=37.9%), (3) Eunicidae (Cn=6.8%), and (4) Nereidae (Cn=2.7%), Pilargidae (Cn=0.3%) and Sabellidae (Cn<0.1%). P. subtilis final body weight varied from a minimum of 4.2 g to a maximum of 9.3 g, with final survival ranging from 42 to 69%. Shrimp predatory pressure produced a reduced polychaete growth in NFS and FS enclosures when compared to other treatments. Polychaete numerical abundance and biomass were greatly affected by higher shrimp stocking densities, while their population patterns appeared to be governed by other environmental and endogenous cues. Artificial feeding promoted higher polychaete levels even when shrimp were present, but it was not effective in alleviating P. subtilis grazing pressure at increased stocking densities (i.e., 15 and 20 shrimp/m2). Results showed that P. subtilis predation, shrimp stocking density and external food supply are major factors to be considered when establishing sustainable limits for polychaete use as a naturally occurring food source in aquaculture systems.

Polyculture of sea scallops (Placopecten magellanicus) suspended from salmon cages

Commercial and developmental operations for the culture of the seascallop, Placopecten magellanicus, are present in AtlanticCanada and New England. In an experiment designed to examine the commercialfeasibility of polyculture of scallops with Atlantic salmon(Salmosalar), we measured growth andsurvival of sea scallops grown in suspension at two salmon aquaculture sites innortheastern Maine (Johnson Cove (JC) and Treats Island (TI)). Sea scallop spatwere grown in pearl nets and deployed on drop lines containing ten nets inAugust 1994. One drop line of ten nets was sampled about every four months andscallops were counted, measured and weighed. Scallop tissues were also analysedfor paralytic shellfish toxins (PSP). The maximum level of PSP recorded duringthe study was 1174 μg STX equiv.·100 gtissue−1 (excluding adductor muscle weight). After one year,shell heights were 53.6 and 56.4 mm, growth rates were 0.11 and0.12 mm per day and wet adductor muscle weights were 3.3 and 4.1g (TI and JC, respectively). These growth rates were comparable tosea scallops grown in suspension culture to a nearby scallop aquaculture siteand other areas in Atlantic Canada. Reduced rates of survival were found duringthe latter part of the experiment and were attributable, in part, to heavyfouling, predators and high stocking density. The potential for supplementalincome, diversification of the salmon aquaculture industry, and feasibility ofculturing scallops at adjacent sites to salmon operations does exist.

Food handling efficiency and particle size selectivity by the southern brown shrimp penaeus subtilis fed a dry pelleted feed

This study investigated the feed handling efficiency and size selectivity of four size groups of Penaeus subtilis fed three commercial feed particle sizes. Shrimp feeding behaviour was recorded with a video‐camera, installed below a glass aquarium, where one shrimp at a time was introduced and allowed to feed. A total of 163 specimens of P. subtilis were examined. Results indicated that over 59% of all food particles placed in the mouth by shrimp were completely or partially consumed, regardless of size. Large pellets however were less preferred than small ones. Manipulation capacity and capture success were also greater when shrimp were fed small particles. Shrimp size had no significant effect on manipulation efficiency, indicating that within the feed size range examined, food handling by juvenile shrimp was as efficient as adults. These results suggest that in aquaculture systems, the use of crumbles and broken pellets may be preferable to large pellets.

Chapter 24 - Aquaculture of the Scallop Nodipecten nodosus in Brazil

The Atlantic lions paw scallop, Nodipecten nodosus, is the largest scallop occurring in Brazilian waters, and it has been the subject of interest for aquaculture development since the early 1990s. For two decades, experimental studies have been conducted on reproduction, larval culture, settlement on artificial collectors, nursery culture and growout. Efforts to establish commercial culture have been carried out in the states of Santa Catarina, Rio de Janeiro and more recently in Sao Paulo. As a result, small-scale commercial culture of this native species is now conducted in these states. Scallop production is still small and mainly carried out on an artisanal scale without the use of mechanisation. In Santa Catarina, most are oyster or mussel producers growing scallops as an additional source of income. In general, after 9–12 months post-nursery, scallop size ranges from 7 to 8 cm yielding an adductor muscle mean weight of 8–12 g. In Rio de Janeiro, scallop farming is mainly a part-time activity in coastal fishing communities in the region of Angra dos Reis and farms are maintained mainly as a subsistence operation. In Sao Paulo, a small-scale operation involving local fisherman is under establishment in the northern part of the state. Current prices of cultured N. nodosus range from US

Scallop Aquaculture and Fisheries in Eastern North America

10 to 16 per dozen when marketed locally or sent to gourmet restaurants in metropolitan areas where prices may reach up to US

Preface from Second Edition

25 per dozen. The culture of Nodipecten nodosus has a large potential for development in Brazil, but certain constraints such as legal aspects for concession of marine leases, lack of access to credit, limited domestic market and high production costs still have to be overcome in order to expand production. Considering the availability of hatchery produced juveniles, adequate marine areas for aquaculture, resistance of the species to withstand husbandry practices, fast growth rates and availability of feasible techniques for nursery, intermediate, and growout cultures, there is a tremendous potential for future expansion of scallop culture production in Brazil.

Scallops : biology, ecology, and aquaculture

Abstract This chapter presents an updated overview of sea scallop aquaculture and calico and bay scallop fisheries, aquaculture and enhancement efforts in eastern North America. It encompasses the relevant biology associated with reproduction, spat collection, juvenile intermediate growout and commercial production. It also addresses some of the species interactions that are occurring during the culture phase such as biofouling, predation and the accumulation of marine biotoxins. The review also addresses some of the extensive aquaculture/stock enhancement initiatives that are currently underway for all three species.

Effect of dietary lipids on fatty acid composition and metabolism in juvenile green sea urchins (Strongylocentrotus droebachiensis)

A few years ago, because of the rapidly growing interest in supramolecular systems capable of performing useful functions, we felt that a monograph was needed to cover the introductory features and present a unifying and stimulating overview of this new frontier of scientific research. We, therefore, decided to write Molecular Devices and Machines: A Journey into the Nanoworld, a book that was published by Wiley-VCH in February 2003. The book was well received in the scientific community, as demonstrated by several flattering reviews published in the most important scientific journals. In 2005 the book was translated in Chinese by Professors He Tian and Liming Wang (East China University, Shanghai) and published by Chinese Chemical Industry Press (Beijing). A Japanese translation is going to be published very soon by NTS, Inc., Tokyo. In the last few years, there has been a continuously growing interest in designing, synthesizing, and operating artificial molecular devices and machines. New fundamental concepts have emerged and a wealth of novel systems have been investigated. In Spring 2006, Wiley-VCH informed us that a few printed copies of our book were still available and suggested that, instead of making a reprint, it would have been more useful for the scientific community to produce a new edition of our monograph. After having consulted several colleagues, we indeed realized that it was the right time to revise and updateMolecular Devices and Machines: A Journey into the Nanoworld. We have kept the title but changed the subtitle to emphasize that it is really a new edition of the same book. Molecular Devices and Machines: Concepts and Perspectives for the Nanoworld indeed maintains the fundamental structure of the previous book, while the content has been substantially changed. The chapters and sections dealing with the fundamental principles have been largely rewritten with the aim of helping the reader to realize emerging trends, to find a sound discussion of fundamental processes like electron and energy transfer, to be cautious about naïve similarities with devices and machines of the macroscopic world, and to understand that the nanoworld is characterized by some unfamiliar features that prevent the realization of nanoscale devices and machines as described in science-fiction films, television series, and novels. The chapters devoted to specific classes of devices and machines have been refreshed and updated, and new chapters have been added. XV