Scyllarus Species Research Articles

Recent advances in larval recruitment processes of scyllarid and palinurid lobsters in Japanese waters

Phyllosoma larvae collected to date in Japanese and Taiwanese waters have been classified into two genera (Linuparus, Panulirus) of the Palinuridae, four genera (Ibacus, Parribacus, Scyllarides, Scyllarus) of the Scyllaridae, and one genus (Palinurellus) of the Synaxidae. However, phyllosoma larvae of three Scyllarus species (S. bicuspidatus, S. cultrifer, S. kitanoviriosus) are absolutely dominant among the larvae collected in the waters. Scyllarus larvae are abundant in coastal waters while those of Panulirus are often collected in offshore/oceanic waters. Based on previous and ongoing studies dealing with spatial distributions of phyllosoma larvae in Japanese and Taiwanese waters, it appears that phyllosoma and nisto larvae of the Scyllarus are retained within coastal waters north of the Kuroshio Current. On the other hand, the life history of the Panulirus (particularly P. japonicus) may be completed within the Kuroshio Subgyre: their phyllosoma larvae may be flushed out from coastal waters into the Kuroshio, then transported through the Counter Current south of the Kuroshio into the water east of Ryukyu Archipelago and Taiwan where they attain the subfinal/final phyllosoma or puerulus stages, once again entering the Kuroshio and dispersing into coastal waters.

Descriptions of phyllosoma larvae of Scyllarus bicuspidatus and S. cultrifer (Decapoda, Scyllaridae) collected in Japanese waters

For understanding larval recruitment processes of Scyllarus and Panulirus lobsters, exact species identifi- cation of field-caught phyllosoma larvae, particularly those of the early stages, is essential. Using ichthyoplankton sam- ples from waters along the west coast of Kyushu to the Japan Sea coast of Honshu and the Kuroshio and Kuroshio- Counter Current regions, we described morphological features of the I to VIII (final) stage phyllosoma larvae of S. bi- cuspidatus and the IV to VIII stage larvae of S. cultrifer. The larvae of equivalent stages of two Scyllarus species are distinguishable from each other by using the combinations of body lengths and morphological features of antennules, pereiopods and pleopods. In addition, a) equivalent larval stages in S. cultifer are always larger than in S. bicuspidatus; b) cephalic shield of S. bicuspidatus is rounder than in S. cultrifer; c) relative to antennule length, the eyestalk is longer in S. cultrifer than in S. bicuspidatus.

Distribution of Scyllarid Phyllosoma Larvae (Crustacea: Decapoda: Scyllaridae) in the Kuroshio Subgyre

Using ichthyoplankton samples collected in the Kuroshio Subgyre during early summer cruises, we examined spatial distributions of scyllarid phyllosoma larvae in the Subgyre, particularly of the genus Scyllarus. The present study has two objectives: (1) to reveal species composition of Scyllarus phyllosoma larvae in the Kuroshio Subgyre, and (2) to examine larval recruitment of Scyllarus species as contrasted with that of Panulirus, particularly P. japonicus, the larval recruitment of which has been examined in detail. A total of 218 phyllosoma larvae collected in the present study belonged to two families (Palinuridae and Scyllaridae) representing 5 genera and 11 species. Phyllosoma larvae of two Scyllarus species (S. cultrifer and Scyllarus sp. c) were abundant among the collected larvae, and were found mainly in the following three regions located within the Kuroshio-Counter Current region south of Kuroshio Current: the water east of Okinawa Is., the water far east of Okinawa Is. (or far south of Shikoku Is.), and the water around Hachijojima Is. Larvae of each of the above two Scyllarus species collected in the three regions may belong to different populations: larvae collected in the water around Hachijojima Is. may come from their benthic populations along the Pacific coast of Honshu and Shikoku Is., central Japan, while larvae collected in the other two regions may come from their benthic populations of the Ryukyu Archipelago and Taiwan. Judging from their shorter larval period and current systems within the Kuroshio Subgyre, these Scyllarus larvae may be destined for death.

Larval stages, developmental ecology, and distribution of Scyllarus sp. Z (probably Scyllarus aoteanus Powell, 1949) (Decapoda: Scyllaridae)

Phyllosomata and nistos of Scyllarus sp. Z taken from plankton around and offshore northern New Zealand and in the Tasman Sea are presumed to be those of S. aoteanus Powell, 1949, the most common Scyllarus species in this area. The full larval and postlarval development of this species are described. Three features are characteristic of Scyllarus sp. Z phyllosomata; a dorsal crest on the cephalic shield, dorsal thoracic spines, and a forked telson in middle stages persisting as two prominent spines outreaching the telson posterior margin in the final stage. Scyllarus sp. Z's closest affinities are with a group of Scyllarus species whose phyllosomata have forked telsons in middle stages and medium to strong posterolateral telson spines in the final stage. The nisto is low in profile but distinctive in its armature. Too few Scyllarus sp. nistos have been described to suggest any group to which that of Scyllarus sp. Z can be assigned. The spatial and temporal distribution of the larvae and postlarvae of Scyllarus sp. Z are also described. Although early larval stages and postlarvae are found close to New Zealand, mid‐ and late‐stage larvae are widely distributed, some well beyond the known latitudinal range of the adults. There is probably an extended egg‐bearing and hatching period as early stage larvae are caught in most months. Variable rates of development of the larvae and/or delayed metamorphosis, are also possible.

First larval stage ofScyllarus posteliforest, 1963 andProcessa macrodactylaHolthuis, 1952 hatched in the laboratory (Crustacea, Decapoda)

Abstract The first larval stage of Scyllarus posteli Forest, 1963, and Processa macrodactyla Holthuis, 1952, are described and illustrated from material reared in the laboratory. For both a diagnostic key for the identification of the first larval stage is provided. For Mediterranean and adjacent Atlantic Scyllarus species have been described but this is the first larval stage of a Scyllarus to be identified with certainty. S. posteli belongs to the second scyllarid group larvae proposed by Sekiguchi (1987), which has four long plumose setae on the distal segment of the maxilla. Processa macrodactyla is characterized by presenting abdominal somite 3 without dorsal spine, four small marginal denticles behind pterygostomian spine, and antennal exopod at least 3/4 the length of antennal scale.

SCYLLARUS RAMOSAE, NEW SPECIES, FROM THE BRAZILIAN CONTINENTAL SLOPE, WITH NOTES ON CONGENERS OCCURRING IN THE AREA (DECAPODA: SCYLLARIDAE)

ABSTRACT Scyllarusramosae, new species, from the Brazilian continental slope closely resembles Scyllarus faxoni from the Caribbean Sea, with which it is compared. Three other species of the genus occur in Brazilian waters, namely, S. americanus, S. chacei, and S. depressus. The old records of S. arctus from Brazil belong actually to S. depressus. A key for the species of Scyllarus from the western Atlantic south of Venezuela is presented.

Phyllosoma Larvae of Scyzlarus Species (Decapoda, Scyllaridae) From the Shelf Waters of Australia

Abstract Zooplankton samples from tropical (the Gulf of Carpentaria and the Northwest Shelf of Western Australia) and temperate (east coast of Tasmania) regions of Australia contained phyllosoma larvae of 14 species of Scyllarus. All but two species were represented at the final, gilled state the exceptions showed intermediary development between subfinal and final stages. Two species were represented as complete larval series, the remainder as incomplete series. The final, or most-developed, stage of the 14 unidentified species, referred to as Scyllarus species A-N in this paper, are described and compared with the literature. Larvae of five species appear to be new larval records for the Indo-West Pacific. Larvae of another three species correspond with those attributed previously to S. rugosus H. Milne Edwards, 1837, S. sordidus (Stimpson, 1860) and S. demani Holthuis, 1946. These, and some other larval identifications or affinities tendered in the literature are examined.

Phyllosoma Larvae of Scyllarus Species (Decapoda, Scyllaridae) From the Shelf Waters of Australia

Phyllosoma Larvae of Scyllarus Species (Decapoda, Scyllaridae) From the Shelf Waters of Australia

Distribution and abundance of scyllarid and palinurid lobster larvae in the Gulf of Carpentaria, Australia

Plankton samples from the Gulf of Carpentaria contained large numbers of the phyllosomata of Scyllarus martensii and an unknown scyllarid species (Scyllarus sp. A) and smaller numbers of the larvae of seven other scyllarid species (Thenus orientalis and six unidentified species of Scyllarus) and three palinurid species (Panulirus homarus homarus, P. versicolor and P. ornatus). The final phyllosoma stage of Scyllarus sp. A is described. The spatial and temporal variabilities of the more abundant scyllarid larvae are described and related to temperature, salinity and plankton biomass. Both S. martensii and Scyllarus sp. A were widespread in the deeper waters of the Gulf, living in a wide range of temperatures (21.7 to 30.3� C) and salinities (28.9 to 34.3). From the range of stages found on six cruises between April 1976 to March 1977, it appears that these two species reproduce throughout the year, although S. martensii had a broad peak period of reproduction from August to November 1976.

Final-stage phylosoma larvae of Scyllarus species (Crustacea : Decapoda : Scyllaridae) from shelf waters of the Great Barrier Reef

Samples of macrozooplankton collected from the shelf area of the Great Barrier Reef (between 18°35′S. and 19°10′S., and 146°30′E. and 147°00′E.) contained phyllosoma larvae of 12 different species of scyllarid lobster. All species were represented at the final stage, three as complete larval series and the remainder as incomplete series. Five species have been identified: Thenus orientalis, Scyllarus martensii, S. demani, S. rugosus and S. sordidus. In this paper the final-stage larvae of S. demani, S. rugosus, S. sordidus and six unidentified Scyllarus species, referred as Scyllarus species A–F, are described and compared with previous references in the literature, and a key developed for their separation.

Identification of late-stage phyllosoma larvae of the scyllarid and palinurid lobsters in the Japanese waters.

Based on zooplankton samples collected in the Kumano-and Enshu-nada seas north of the Kuroshio Current, phyllosoma larvae were examined, with the result that those of eleven species, belonging to five genera Ibacus, Parribacus, Scyllarides and Scyllarus (Scyllaridae) and Panulirus (Palinuridae), are identified. Among these larvae, five species of Scyllarus and two species of Panutirus are described herein. Further, keys to the genus and species of late stages of scyllarid and palinurid phyllosoma larvae in the Japanese waters are represented.

Descriptions of the nisto stage of Scyllarus demani Holthuis, two unidentified Scyllarus species, and the juvenile of Scyllarus martensii Pfeffer (Crustacea : Decapoda : Scyllaridae), reared in the laboratory; and behavioural observations of the nistos of S. demani, S. martensii and Thenus orientalis (Lund)

Live final-stage phyllosoma larvae of T. orientalis, S. martensii, S. demani, and an unidentified specimen, Scyllarus sp. A, were obtained from the mid-shelf region of the Great Barrier Reef. While held in the laboratory, larvae of all species metamorphosed to the subsequent, nisto, stage; the nisto of S. martensii developed further to the first juvenile phase. An additional, nisto, Scyllarus sp. B, obtained in a plankton sample, remains unidentified. In this paper, the nistos of S. demani, Scyllarus sp. A, and Scyllarus sp. B, and the juvenile of S. martensii are described; and behavioural observations of live material, including nistos of T. orientalis, are discussed.

A new species of Scyllarus (Crustacea Decapoda Palinuridea) from the Pacific Ocean

A new species of Scyllarus (Crustacea Decapoda Palinuridea) from the Pacific Ocean

The early larval development of the scyllarid lobster Scyllarides aequinoctialis (Lund) in the laboratory, with a revision of the larval characters of the genus

Larvae of Scyllarides aequinoctialis reared through eight stages during three months in the laboratory at 24° ± 1°C were still in a relatively early phas of development. The reared stages and later phyllosomas of this species obtained from plankton are described and illustrated, as are the last three stages of a different species, probably Scyllarides nodifer. Records of larvae attributed to Scyllarides are reviewed. Most phyllosomas previously assigned to the genus belong to various species of Scyllarus. Larvae of Scyllarides have been erroneously identified as Thenus or Parribacus. The larval characters of the genus are revised in the light of present findings. Phyllosomas of Scyllarides fall into two groups according to the development of the fifth pereiopod. In one group the latter becomes well developed at a relatively early stage ( S. aequinoctialis, S. astori); in the other it remains rudimentary throughout larval development ( S. nodifer, S. latus, S. herklotsii). Although the length of larval life of Scyllarides cannot be accurately estimated, complete development undoubtedly requires several (perhaps 8 or 9) months.