Jiro Kittaka

Culture of phyllosomas of spiny lobster and its application to studies of larval recruitment and aquaculture

Complete larval development of spiny lobsters in culture has been achieved for cool temperate species, Jasus lalandii (H. Milne Edwards, 1837), Jasus novaehollandiae Holthuis, 1963, Jasus edwardsii (Hutton, 1875), Jasus verreauxi (H. Milne Edwards, 1851) and Palinurus elephas (Fabricius, 1787), and a warm temperate species, Panulirus japonicus (Von Siebold, 1824) since 1987. A good survival rate of about 10% was obtained for J. verreauxi. The factors important to the successful larval culture were: (1) introduction of microalgae into the culture water, (2) feeding with mussels and (3) supply of water from the bottom of the culture tank to induce a continuous circular current in the tank. The shortest duration of the phyllosoma stage for the above species, respectively, was 306, 319, 212, 197, 132, and 307 days. The number of instars was 17 for Jasus spp., 9 (estimated) for P. elephas and 25 (estimated) for P. japonicus. The shortest duration of the pucrulus stage was 19, 12, and 11 days for the above animals, respectively. Jasus verreauxi may be suitable because of its potential for a high survival rate. Palinurus elephas is also an interesting possibility because of its short larval life. Duration of the larval stage seems to be species specific. Within a species, it is affected by water temperature and food availability for the phyllosoma but exclusively by water temperature for the puerulus.

Comparative Morphology of the Mouthparts and Foregut of the Final-Stage Phyllosoma, Puerulus, and Postpuerulus of the Rock Lobster Jasus Edwardsii (Decapoda: Palinuridae)

ABSTRACT The gross morphology and fine structure of the mouthparts and foregut of the rock lobster Jasus edwardsii were studied in its late larval and early juvenile stages. The stage-XI phyllosoma has third maxillipeds with specialized setae, second maxillipeds and first maxillae with strong setae, mandibles with well-developed molar and canine-like processes and teeth, and a foregut with well-developed grooves and brushes but no gastric teeth. The first-molt juvenile has third and second maxillipeds and first maxillae with rows or tufts of numerous strong setae, wellcalcified mandibles with strong molar and incisor processes, and a foregut with well-developed ossicles, grooves, brushes, and strong gastric teeth. In contrast, the puerulus has maxillipeds and maxillae with only small numbers of setae, uncalcified mandibles with a rudimentary incisor, and a foregut with a small number of ossicles and setae, and rudimentary lateral teeth. These observations suggest that the late-stage phyllosoma of J. edwardsii feeds primarily on large, soft materials and the early postpuerulus on hard, as well as soft, materials. In contrast, the puerulus probably does not feed during some or all of its existence, and any feeding is on small, soft materials. Use of nutrients stored in the digestive gland is one possible way that the puerulus could meet its energy requirements.

Structural changes in the hepatopancreas of the rock lobster, Jasus edwardsii (Crustacea: Palinuridae) during development from the puerulus to post-puerulus

There is evidence for non-feeding in pueruli of palinurid lobsters during their long-distance swim to the coast and the succeeding post-settlement phase until they molt to the juveniles. For a better understanding of the nutritional supply during the puerulus stage, structural changes in the hepatopancreas were studied in post-settlement pueruli and first-molt, postpueruli of the rock lobster, Jasus edwardsii, collected on the southeast coast of the North Island, New Zealand between 1989 and 1990. In newly settled (transparent) pueruli, the epithelium of the hepatopancreas is dominated by presumed “young R-(resorptive) cells”, which are devoid of lipid droplets, but show active uptake of material from the hemolymph through pinocytosis at the basal region. In the fully pigmented puerulus, the hepatopancreas is dominated by R-cells containing massive lipid droplets; also present are small numbers of F-(fibrillar) and B-(blister-like) cells. This increase of lipid inclusion in the R-cells corresponds to the reduction in size of the fat bodies as the lobster develops from the transparent to the pigmented puerulus. After the molt to the post-puerulus, the R-cells are compressed, and the lipid droplets almost disappear, while the B-cells increase both in size and number. A mechanism is proposed in the present paper to explain energy storage and utilization during the puerulus and post-puerulus stages, wherein the fat bodies and the lipid inclusions play a vital role.

Development of the red rock lobster, Jasus edwardsii, from egg to juvenile

Abstract Mature red rock lobster, Jasus edwardsii were air freighted from the North Island, New Zealand to Japan in 1985. During most years since, egg extrusion has taken place during November and December and egg hatching from February to April. In the main experiment, phyllosomas were cultured in 100‐litre containers. Each container had an upwelling system, connected either to a Nanno‐chloropsis culture tank (Experiment 1) or to a coral sand filter tank (Experiment 2). Artemia nauplii and mussel gonad were the main foods provided. The numbers of 1st, 5th, and 15th instars were 12 000, 1500, and 137 respectively in Experiment 1, and 1500, 99, and 67 in Experiment 2. The intervals between Instars 1–4 and 4–14 were 43 and 175 days respectively for Experiment 1, and 43 and 169 days for Experiment 2. In Experiment 1, nine phyllosomas (13–15th instar) died during metamorphosis to the puerulus and a single 17th instar metamorphosed 303 days after hatching, 19 days later moulting into the juvenile. In Experiment 2, six 17th instar larvae metamorphosed 293 days and more after hatching, with all dying over the following 3 days. In an ancillary experiment, 30 phyllosomas were cultured in each of two 30‐litre tanks containing microalgae: survival was higher, 20% and 43% reaching Instars 14/15 and six metamorphosing after 212–274 days. In all experiments, the developmental sequence was generally consistent with that for larvae from the field. Gill buds appeared at the 13th instar and gills were complete at the 17th instar. Improved culture methods are required to reduce late‐stage mortalities.

Histological Characteristics of Fat Bodies in the Puerulus of the Rock Lobster Jasus Edwardsii (Hutton, 1875) (Decapoda, Palinuridae)

The histochemical characteristics of fat bodies in the hemocoel of the puerulus and the postpuerulus of the New Zealand rock lobster Jasus edwardsii were examined. Each fat body spread from the distal tip of the anterior and intermediate lobes of the hepatopancreas to the hemocoel between the branchiostegite wall and inner carapace wall. The fat bodies stained intensively blue with Nile blue and blue black with Sudan black B and were PAS positive, suggesting that they contained acidic lipid and polysaccharides. The fat bodies got smaller as the lobsters developed, particularly as they changed from transparent to pigmented pucrulus. This reduction in size of fat body corresponded with increased lipid in the hepatopancreatic cells. These results suggest that the fat bodies are storage sites of nutrients which would provide a source of metabolic energy both for the active, long-distance swim by the puerulus and for subsequent developmental changes after settlement.

Lectins in the Rock Lobster Jasus Novaehollandiae Hemolymph

Hcmolymph of three different species of rock lobsters was examined for its agglutinating activity using mammalian erythrocytes and bacteria. The hemolymph of the red rock lobster Jasus novaehollandiae agglutinated human ABO erythrocytes and also a marine bacterium Pseudomonas aeruginosa. The hemagglutinating activity was, however, inconsistent, and varied from a titer of 4 to 1024 for human erythrocytes. J. novaehollandiae lectins were heat-labile and the hemagglutinating activity was dependent on the presence of Ca2+. The major lectin named JN-2 was a glycoprotein having a molecular weight of 400,000 and dissociated into subunits of different molecular sizes (85, 81, and 63kD). Porcine stomach mucin (PSM), asialo-PSM, and fetuin were effective inhibitors to J. novaehollandiae lectins. N-acetylneuraminic acid did not inhibit the hemagglutinating activity. Simple sugars such as D-ribose, D-arabinose, and D-galactose also inhibited the hemagglutinating activity to some extent. Another species of the red rock lobster J. edwardsii was found to possess lectins similar to those of J. novaehollandiae. On the contrary, the humoral lectin(s) of the green rock lobster J. verreauxi was sialic acid-specific, and the lectin activity was independent of the presence of Ca2+.

Occurrence of Pueruli of Jasus Verreauxi (H. Milne Edwards, 1851) (Decapoda, Palinuridae) in Waters Off Cronulla, New South Wales, Australia

Artificial seaweed collectors set near the surface and crevice collectors set near the bottom were placed in waters of 10 m depth off Cronulla in an attempt to capture pueruli of Jasus verreauxi, which had not previously been studied in any detail in Australia. All pueruli and post-pueruli of J. verreauxi caught were found on collectors set near the surface, between October and December 1992.

Experimental Culture of the American Lobster (Homarus Americanus) Utilizing Warm Waste Water From a Power Station in Japan

[The American lobster was cultured experimentally at Hayama, in seawater controlled between 16° and 20°C to investigate the advantages of utilizing warm waste water from a power station. The survival rate was improved by using an open (flow-through) rearing system where the lobsters were reared under dark conditions and seawater was disinfected by ultraviolet light. Bacterial number was reduced from 3.4-37.5 x 103 to 0.7-4.3 × 103 CFU/ml by ultraviolet treatment. The rearing results were compared with those obtained at Sanriku, using ambient seawater between 10° and 20°C. Growth rate was faster at Hayama than at Sanriku. With these rearing conditions at Hayama, the lobsters might be raised to marketable size within 3 years., The American lobster was cultured experimentally at Hayama, in seawater controlled between 16° and 20°C to investigate the advantages of utilizing warm waste water from a power station. The survival rate was improved by using an open (flow-through) rearing system where the lobsters were reared under dark conditions and seawater was disinfected by ultraviolet light. Bacterial number was reduced from 3.4-37.5 x 103 to 0.7-4.3 × 103 CFU/ml by ultraviolet treatment. The rearing results were compared with those obtained at Sanriku, using ambient seawater between 10° and 20°C. Growth rate was faster at Hayama than at Sanriku. With these rearing conditions at Hayama, the lobsters might be raised to marketable size within 3 years.]

Discovery of Pueruli of Panulirus Japonicus (Von Siebold, 1824) On the Northeast Pacific Coast of Japan

A puerulus and five postpueruli of Panulirus japonicus were captured on the Sanriku coast in northeast Japan, from Okkirai Bay in the north to Sendai Bay in the south, in December 1991 and January 1992. Branches of the Kuroshio Current of 20°C or more, approached the Sanriku coast in early October and in early November, 1991. Cultured larvae showed that the duration of the puerulus stage was 15.3 days at 24-25°C. Puerulus swimming duration was estimated to be about seven days. These findings suggest late-stage phyllosomas are transported by the Kuroshio Current towards the coast.