Nisto Stage Research Articles

New records of introduced species in the Mediterranean Sea (November 2023)

This collective article presents new information about 15 introduced taxa belonging to five phyla: one Rhodophyta, one Chlorophyta, one Mollusca, one Annelida, two Arthropoda, and nine Chordata (one Ascidiacea and eight Osteichthyes). The records refer to eight Mediterranean countries and extend from the Alboran Sea to the Levantine Sea as follows: Spain: first record of the African hind Cephalopholis taeniops for the Alboran Sea, and a further record of the Monrovia surgeonfish Acanthurus monroviae, extending its distribution northwards in the Western Mediterranean. Italy: an additional record of the squat lobster Scyllarus subarctus based on its nisto stage, new records of the lionfish Pterois miles in the north-western Ionian Sea, first records of the bivalve Fulvia fragilis for the Italian Adriatic coast, and a record of the amphipod Ptilohyale littoralis in the northern Adriatic Sea, also representing the first report for the Mediterranean Sea. Montenegro: first record of the non indigenous ascidian Ciona robusta. Albania: first record of the red cornetfish Fistularia petimba. Greece: first record of the cryptogenic polychaete Alitta succinea in association with ship fouling, suggesting the possibility of a non-indigenous origin of Mediterranean populations of this species, and first record of the Seychelles dragonet Synchiropus sechellensis for the Saronikos Gulf. Türkiye: first record of the red alga Womersleyella setacea, report of an abundant population of the Indian twospot cardinalfish Cheilodipterus novemstriatus in the Turkish Aegean Sea, and first record of Synodus randalli, also corresponding to the first report for the Mediterranean Sea. Syria: first record of the blenny Istiblennius cf. meleagris. Israel: report of an algal bloom of the green alga Codium parvulum, and first record of Synchiropus sechellensis.

Finding the Missing Puzzle Piece of the Nisto Stage in the Larval Cycle of the Slipper Lobster Scyllarides squammosus: A Molecular and Morphological Approach.

Slipper and spiny lobsters are crustaceans that are in high demand and possess great commercial potential as valuable foods. The early life stages are important to understand the distribution and resource ecology of those lobsters. However, much less information is available about slipper lobsters than spiny lobsters. Biological information concerning the transition stage from the planktonic to the benthic phase, the so-called nisto stage, is limited probably due to its short duration. An individual scyllarid nisto was discovered while scuba diving off Chichijima Island. DNA analyses using mitochondrial 16S rRNA and cytochrome c oxidase subunit 1 (COI) genes confirmed this specimen to be Scyllarides squammosus (H. Milne Edwards, 1837). Detailed morphological observations of this specimen and its comparison with previous reports on Scyllarides nistos suggest that the diagnostic character of S. squammosus nisto is the pleura of the second to fifth pleonites possessing prominent teeth entirely on the lateral margin. Other morphological characteristics are the carapace with the widest distance in the middle and the second to fifth pleonites bearing two tubercles on each side. This report describes the identification of the first worldwide record of a Scyllarides nisto, confirmed by molecular barcoding.

Growth and biochemical composition of hatchery reared Scyllaridae lobster (Thenus australiensis) larval stages, nisto and juvenile first stage

Understanding the nutrition of lobster larvae through the examination of growth and biochemical composition across different life stages is a critical component of aquafeed development of new aquaculture species. Therefore, in the present study, we benchmarked growth and changes in biochemical composition of Thenus australiensis from first larval stage (S1) to the juvenile first stage (J1). The larval cycle was completed in a maximum duration of 31 d and comprised four successive larval stages followed by a post-larvae stage (nisto) and a subsequent moult to J1. Growth during all larval stages, metamorphosis to nisto, and moult to J1 were tracked through the measurement of size (total length, TL and cephalic/carapace width, CW), individual wet (WW) and dry (DW) weights. Bulk samples of all developmental stages were collected and analysed for ash, crude protein, total lipid, nitrogen free extract (NFE) and gross energy of dry matter (DM). Lipid class, fatty acid and mineral composition of S1, S4 and J1 of DM were also measured to provide more detailed analysis of composition. As expected, TL, CW, WW and DW increased with each subsequent stage except for lower TL and CW of the nisto stage when compared to S4 larvae. The DW increases throughout larval development until nisto and was defined by higher ash, crude protein, total lipid and NFE absolute amounts. However, from nisto to J1, total lipid decreased by half. The total lipid of DM increased as larval stages progressed to the nisto phase, declining rapidly when monitored at J1. The accumulation of lipid during the larval phase highlights the importance of building lipid stores to maintain metabolism during the non-feeding nisto stage and moult to J1. Polar lipid was the dominant lipid group in comparison to neutral lipids stores. The energy content of larvae, nisto and J1 reflected the accumulation of lipid over the larval stages and its depletion during the non-feeding nisto stage. The environmental influence on elemental uptake was evident at the moult to J1 with a >4-fold increase in ash content in individual J1 compared to nisto. This was supported by an increase of major mineral constituents of the exoskeleton, particularly, calcium. The present study is the first describing in detail the growth and biochemical composition of all the larval stages until J1 for T. australiensis. The new knowledge on nutrition will support progress in aquafeed development for this new aquaculture species.

Morphological descriptions of laboratory reared larvae and post-larvae of the Australian shovel-nosed lobster Thenus australiensis Burton & Davie, 2007 (Decapoda, Scyllaridae)

Complete larval development from newly hatched larvae up to the juvenile stage was successfully achieved in the Australian shovel-nosed lobsterThenus australiensisunder laboratory conditions. The larvae of this species passed through four phyllosoma stages (each stage has a single instar), and developed into the first juvenile stage via a post-larval, nisto stage. The shortest and mean durations from hatching to metamorphosis at a water temperature of 25°C were 32 and 38 days, respectively. Morphologies of body and appendages for all four phyllosoma stages and the nisto stage were described. The phyllosomas were fed exclusively on the jellyfishAurelia auritathroughout their culture. Our results indicate that jellyfish may be a viable diet forT. australiensisphyllosoma’s in culture and may therefore be useful for commercial-scale lobster production.

The complete larval development of Ibacus ciliatus from hatching to the nisto and juvenile stages using jellyfish as the sole diet

Phyllosomas of scyllarid lobsters are known to associate with jellyfish in the wild, suggesting that they prey on a wide variety of gelatinous zooplankton species. To investigate the potential of utilizing jellyfish as a diet for Ibacus ciliatus phyllosomas in culture, 22 newly hatched phyllosomas were reared individually and fed with the jellyfish Aurelia aurita and Chrysaora pacifica throughout the rearing period. Of the 18 phyllosomas that survived to stage VII, nine directly metamorphosed into the nisto stage 66.8days (range: 65–70) after hatching. Among them, five nistos successfully molted into the juvenile stage 85.0days (range: 83–87) after hatching. On the other hand, eight of the phyllosomas at stage VII molted through an extra instar. Four metamorphosed into the nisto stage 79.3days (range: 76–82) after hatching; however, these nistos failed to molt into the juvenile stage. Significant differences of the body length between the phyllosomas with and without an extra instar were observed after stage V. The addition of an extra instar in phyllosomas at stage VII may have been caused by the insufficient nutritional conditions during the earlier stages. Complete larval development from hatching to the juvenile stage in I. ciliatus was observed for the first time. Our method of using jellyfish as diet may be useful for improving the aquaculture techniques of I. ciliatus, and other species.Statement of relevancePhyllosoma has been known as a gelatinous zooplankton feeder in the wild. The most important finding in the present paper is that phyllosomas of the scyllarid lobster I. ciliatus can grow into the juvenile stage with feeding on jellyfish. The previous studies have tried to rear I. ciliatus phyllosomas with feeding clams or mussels, and observed that phyllosomas successfully metamorphosed into the nisto stage. However, no one has achieved to obtain the juveniles in culture. We utilized jellyfish as diet for phyllosomas. Consequently, the complete larval development from the newly hatched phyllosoma to the juvenile stages was observed for the first time. Jellyfish has been successfully applied as diet for phyllosoma only in the scyllarid lobster Ibacus novemdentatus until today, so that the present experiment is the second successful achievement. This result suggests that growth and survival rates of scyllarid lobster phyllosoma may be improved by use of jellyfish as diet for phyllosoma in their hatchery.Although the nutrition level of the gelatinous zooplankton has been known to be low, survival and growth rates of phyllosoma which fed on gelatinous zooplankton have been higher than those of phyllosoma which fed on other diet containing much nutrition. Similar results have been obtained in several species of fish. Therefore, we emphasize in this manuscript that the utilization of jellyfish as a nutritional resource for the fish and crustacean aquaculture should be further studied.It is considered that the extra molting may be added under conditions where larvae are unable to obtain sufficient energy reserves for growth and metamorphosis. Such conditions are mainly caused by inadequate nutritional quality; however, there is limited information of the critical timing at which the addition of the extra molting is determined. In our experiments, significant differences of body length between the phyllosomas having an extra molting and the phyllosomas without extra molting were started to be observed during the early stage of phyllosomas. Our results suggest that, in decapod crustaceans, the mortality of decapodid and juvenile stages may be affected by insufficient energy reserves during the early larval stages.

Differences in the biochemical compositions of two dietary jellyfish species and their effects on the growth and survival ofIbacus novemdentatusphyllosomas

Phyllosomas (planktonic larvae) of slipper lobsters cling onto and feed on jellyfish under both natural and laboratory conditions. Phyllosomas of Ibacus novemdentatus are capable of feeding on various jellyfish species including venomous stingers; however, the range of jellyfish species capable of supporting the growth and survival of phyllosomas is unknown. Seventeen (12 for the first and five for the second trials) and 18 (13 for the first and five for the second trials) phyllosomas were fed exclusively on the jellyfish Aurelia aurita and Chrysaora pacifica, respectively. Aurelia aurita-fed phyllosomas metamorphosed into the nisto stage (postbenthic larvae) ∼54 days after hatching, whereas C. pacifica-fed phyllosomas did not. Major nutritional compositions such as amino acids, fatty acids and minerals were compared between the two jellyfish species. The proportion of each major nutritional component was not significantly different between the two jellyfish species, suggesting that C. pacifica was not nutritionally inferior to A. aurita. Therefore, the observation that the C. pacifica-fed phyllosomas did not metamorphose into the nisto stage was not because of major nutritional compositions but due to other factors such as the lack or excess of other minor nutrients, or the species-specific texture of the jellyfish.

Complete larval development of Thenus unimaculatus Burton & Davie, 2007 (Decapoda, Scyllaridae)

Larval development of the shovel-nosed lobster Thenus unimaculatus Burton & Davie, 2007 is described based on laboratory studies. The larval stages included four stages of phyllosoma (I-IV), followed by a post larval, non-feeding nisto stage which metamorphosed to the juvenile stage, also known as first seed. The nisto stage is reached in 26-30 days, the average duration of each phyllosoma (I-IV) and nisto was 7, 5, 7, 7 and 4 days, respectively. The phyllosomas are characteristically flattened, leaf-like, transparent planktonic larvae, while the nisto, translucent in appearance, remains sedentary at the bottom. The first juvenile stage has a hard exoskeleton and feeds on fresh clam meat. The survival rate from phyllosoma I to nisto was 22%.

Culture of phyllosomas of Ibacus novemdentatus (Decapoda: Scyllaridae) in a closed recirculating system using jellyfish as food

The complete larval development of a slipper lobster, Ibacus novemdentatus, from newly hatched phyllosomas to juveniles fed only jellyfish, was successfully achieved. Most larvae passed through 6 phyllosomal and 1 nisto stages. The phyllosomal duration was shorter than that reported in previous studies; notably the 7th larval stage was skipped. This is the first report on the complete phyllosomal development with jellyfish as the sole food source. Moreover, the phyllosomas were reared under either closed recirculating or static conditions, where the shortest duration of phyllosomas was 44 and 41days, respectively. Finally, 12.5% of phyllosomas in recirculating condition and 36.1% in static condition metamorphosed into nistos. We conclude that phyllosomas of I. novemdentatus could metamorphose into nisto in a labor-saving closed recirculating system furnished with ultraviolet sterilization and foam fractionation. The results indicate that mass production of phyllosomas in I. novemdentatus, reared solely on jellyfish in recirculating system, is feasible.

The true identities of the slipper lobsters Nisto laevis and Nisto asper (Crustacea: Decapoda: Scyllaridae) verified by DNA analysis

In 1885, Sarato created Nisto as a new genus of slipper lobster and assigned two species to his taxon, namely Nisto laevis and N. asper. Bouvier later regarded these two species as post-larval stages of Scyllarus arctus (Linnaeus, 1758). This viewpoint of two post-larval stages has been accepted and retained, including being cited in the most recent scyllarid literature. The discovery of N. laevis and N. asper specimens in the reference collection of the Natural History Museum, London and the capture of three nisto-stage individuals, one in the north-western Mediterranean Sea and two in the Gulf of Cádiz (eastern Atlantic Ocean) have facilitated a historical review into the post-larval stages of S. arctus, as well as new detailed morphological descriptions. From the present study, it has been possible to describe and illustrate the nisto stages of S. arctus and S. pygmaeus (Bate, 1888) and to resolve the true identities of N. laevis and N. asper by DNA analysis. Accordingly, N. laevis has been identified as the nisto stage of S. pygmaeus and N. asper as that of S. arctus.

Phyllosoma and nisto stages of Scyllarinae sp. D (Crustacea: Decapoda: Scyllaridae) from the south-west lagoon of New Caledonia

The phyllosomas and nisto of an unknown species of Scyllarinae (Scyllarinae sp. D) are described from the lagoon at New Caledonia. Developmental stages of Scyllarinae sp D are of medium size compared to those of other scyllarine lobsters and morphologically similar to those of previously described species in the subfamily. Seven phyllosoma stages and a single nisto stage are distinguished. Phyllosomas and nistos were collected at Ricaudy Reef inside the southwest area of the lagoon, which is delimited by an almost continuous barrier reef. The entire development of Scyllarinae sp. D is likely to occur in lagoon waters. Scyllarinae sp. D probably represents one of 14 scyllarine species recorded from New Caledonia but not the five species Eduarctus martensii (Pfeffer, 1881), Scammarctus batei (Holthuis, 1946), Galearctus timidus (Holthuis, 1960), G. kitanoviriosus (Harada, 1962), Crenarctus bicuspidatus (De Man, 1905), for which some or all phyllosoma stages have been reliably identified. The nisto is similar to, but quite distinguishable from, that of G. kitanoviriosus.

Complete larval development of a scyllarine lobster, Galearctus kitanoviriosus (Harada, 1962) (Decapoda: Scyllaridae: Scyllarinae), reared under laboratory conditions

Complete larval development of a scyllarine lobster, Galearctus kitanoviriosus (Harada, 1962), is described and illustrated from laboratory-reared material. The development comprises nine phyllosoma stages and one nisto stage. Nistos appeared 52-59 days and first stage juveniles 65-77 days after hatching, under rearing conditions with 24.3-25.5℃ water temperature and a salinity of 34.0-35.0‰. The morphological characteristics of phyllosoma and nisto stages were compared with those of other scyllarine larvae, which were also described from laboratory-reared materials. Galearctus kitanoviriosus phyllosomas can be differentiated from other species by characteristics of the cephalon, maxillule, and pereiopods. The nistos of G. kitanoviriosus can also be distinguished from those of Chelarctus cultrifer (Ortmann, 1897) and Petrarctus demani (Holthuis, 1946) by the armature and setation of the antenna, maxillule, and abdominal segments.

COMPLETE DEVELOPMENT AND COMPARATIVE MORPHOLOGY OF LARVAL THENUS ORIENTALIS AND THENUS SP. (DECAPODA: SCYLLARIDAE) REARED IN THE LABORATORY

ABSTRACT Newly hatched phyllosomas of 2 species of Thenus, T. orientalis and Thenus sp., were successfully reared to the juvenile stage under laboratory conditions. Separate cultures of phyllosomas of T. orientalis were fed on 4 food regimes consisting of fresh flesh of Donax brazieri, frozen flesh of D. brazieri, frozen gonad of Perna canaliculus, and nauplii of Artemia. Phyllosomas of Thenus sp. were fed only on fresh flesh of D. brazieri. For rearing both species, water temperature was maintained at 27.0 ± 0.5°C. All phyllosomas of the 2 species of Thenus fed on fresh flesh of D. brazieri developed through 4 phyllosomal instars, equivalent in development to the 4 larval stages of T. orientalis previously described from planktonic material. The morphology of these 2 species of Thenus at the phyllosomal and nisto stages were compared. The mean number of paired exopodal setae on pereiopods and the total body length of the phyllosomas differed between the two species which were fed fresh flesh of D. brazieri. Phyllosomas of T. orientalis fed on frozen food (D. brazieri or P. canaliculus) showed poor survival, prolonged duration of instars, and poor molt increments. Furthermore, approximately 50% of these phyllosomas developed an extra instar (fifth instar) before metamorphosing to the nisto stage. One diagnostic character, the ornamentation of the anterolateral margin of the antennule, was consistent throughout all cultures of both species and identified the larvae of each species. In all instars of T. orientalis, there was a short terminal spine on the anterolateral margin of the antennule, whereas in Thenus sp. a short seta was present in this position. However, no morphological differences were found to distinguish between the nistos of the two species.

Development of the proventriculus in larvae of the slipper lobster, Ibacus ciliatus (Decapoda: Scyllaridae)

The morphological development of the proventriculus in the phyllosomal and nisto stages of the scyllarid slipper lobster is described and illustrated. Possible flow pathways of food particles is deduced from the structure of the proventriculus. Through all phyllosomal stages, no gastric teeth or cardio-pyloric valve are found, the proventriculus consisting of a straight tube in sagittal views. A series of grooves, spines, setae and brushes are found, and the posterior filter-press is well-developed except in newly hatched (1 st stage) larvae. It is concluded that the major function of the phyllosomal proventriculus is the filtering of food particles previously masticated by the mouthparts. By contrast, the proventriculus in the nisto stage is very different from that of the phyllosoma, being similar to that of adult lobsters. The proventriculus in the nisto stage is divided into two principal chambers (the anterior and posterior) by the cardio-pyloric valve which is formed from folds in the wall. This valve is absent from the phyllosomal proventriculus. On the other hand, in the nisto, the lateral teeth, spines, setae, grooves and filter-press are less developed than those of the phyllosomal stage. Similarly, the chitinous wall is un-calcified, and thus calcified gastric teeth are absent from the proventriculus of the nisto. These results suggest the absence of phyllosoma-like filtering and the development of juvenile/adult masticating functions in the proventriculus of the nisto. Dietary changes would therefore be expected to occur when the planktonic phyllosoma larvae metamorphose into the nisto stage, which is transitional between the planktonic phyllosoma and the benthic juvenile.

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.

Description, distribution and abundance of late larval stages of the Scyllaridae (slipper lobsters) in the south-eastern Indian Ocean

Plankton samples from the south-eastern Indian Ocean between 25�30's. and 35�00'S. and from the Western Australian coast out to 99� 00'E., showed the presence of several species in three genera of the Scyllaridae; Scyllarides sp. a; Scyllarus demani; Scyllarus bicuspidatus; Scyllarus spp. a, b, and c; Ibacus peronii and Ibacus sp, a. The final (gilled) phyllosoma and nisto stages of previously undescribed species are described. A generic key to the final phyllosoma of the Palinuridae, Scyllaridae and Synaxidae recorded from the southern Indian Ocean is presented. The distribution of the catches of the phyllosoma of Scyllarus bicuspidatus, Scyllarus sp. b, Ibacus peronii and Scyllarides sp. a and data on the seasonal catches of all scyllarid species are presented. The phyllosoma of S. bicuspidatus undergo diel migrations. Early-stage densities peak at depths of 40-80 m during the day, and mid and late stages peak at 80-100 m. At night the early stages are found at the surface, independent of moonlight intensity. Mid and late stages peak at the surface only on moonless nights. On moonlit nights the density of mid and late stages peak at 15-25 m depth.