Scyllarides Latus Research Articles

Nature reserves facilitate conservation of the Mediterranean slipper lobster Scyllarides latus

The Mediterranean slipper lobster Scyllarides latus is a large and commercially valuable crustacean that has become less common in recent years due to overfishing. Adults follow a seasonal pattern: during their inshore reproductive season they shelter during daytime in rocky caves and crevices along the shallow Mediterranean shelf, while in fall they are assumed to migrate into deeper water. Our goal was to determine whether rocky marine reserves, already proven to successfully protect species with limited movement, can also facilitate conservation of the migratory S. latus. We used underwater daytime surveys to study S. latus abundance, density, sex, size, and the presence of berried females in the Rosh Hanikra-Achziv Marine Reserve along the northern Israeli Mediterranean coast. We also tagged lobsters inside the reserve with T-bar tags and tracked their activity using acoustic sensors. Acoustic telemetry revealed that S. latus was mostly nocturnal and mainly found in the deeper part of the reserve. We found higher abundance, higher density, and larger mean lobster size in the reserve compared to a nearby unprotected control site with similar topography and depth range. Thirty percent of the marked lobsters were subsequently recaptured inside the reserve. Recaptures, both during the same season and between seasons, indicated individual fidelity to specific dens. Our findings suggest that a well-protected reserve can enhance the conservation of S. latus. Since lobster size is positively correlated with reproductive potential in both sexes, reserves can also serve as a refuge, supplying propagules and juveniles to unprotected areas.

Increasing seawater temperatures in the Levantine Basin, eastern Mediterranean, may elicit increased activity in slipper lobsters, Scyllarides latus (Latreille, 1803) (Decapoda: Achelata: Scyllaridae)

Abstract Temperature is a predominant motivator for movement and activity over a wide range of mobile marine ectotherms. Water temperature modulates the movements of many lobster species, which can vary widely over spatial and temporal scales. Providing insight into the thermal preferences (and refuges) that some lobsters seek remains a key tenet to our understanding of the behavioral ecology of these animals. The Mediterranean slipper lobster, Scyllarides latus (Latreille, 1803), shows seasonal movements throughout most of its range and is subject to a changing thermal environment. Through a series of laboratory-based trials, we examined the movement activity of S. latus and tested the hypothesis that S. latus engage in increased movements when subjected to temperatures outside their preferred range. To examine this, we exposed a set of lobsters (N = 10, CLavg= 83.1 ± 6.1 cm) to the same thermal profiles as in the field and assayed their locomotion using activity wheels. Our laboratory results showed that individuals of S. latus are more active at higher temperatures during dawn hours and revealed that warming water temperatures elicited markedly longer movements over a similar timeframe. Combined, these findings suggest that increasing water temperatures in the eastern Mediterranean (Levant) may affect lobster movements and could alter seasonal patterns of distribution as well.

Marine rocky reef assemblages and lithological properties of substrates are connected at different ecological levels

Recent studies suggest that the lithological properties of hard substrates play an important role in influencing the diversity and structure of marine assemblages involving macroalgae, sessile organisms and vagile animals like heterobranchs gastropods and fishes. The present study aims at exploring whether the influence of different substrates (limestone vs granite) could drive the occurrence of different vagile groups (crustacean decapods, echinoderms and fishes). The study was carried out at the “Tavolara-Punta Coda Cavallo” Marine Protected Area (NE Sardinia, Mediterranean Sea) where substrates of different lithology, namely granites and limestones, occur on a local spatial scale. The diversity and the abundance of 16 vagile species (four crustaceans, seven echinoderms and five fishes) were investigated by the analysis of photographs (2352 images) collected in 20 sites (10 limestones and 10 granites), between 30 and 50 m depth. Statistical analyses showed a clear-cut separation between the assemblages assessed on the two lithological substrate types, with assemblages on granites that were tightly grouped and those on limestones more dispersed. The total species richness did not significantly vary between limestones and granites. Galathea strigosa and Marthasterias glacialis were exclusively recorded on granites, while Palinurus elephas, Scyllarides latus, Arbacia lixula, Ophidiaster ophidianus and Serranus scriba were exclusively found on limestones. The observed patterns could be partially explained by multiple factors related to lithology: i) the different availability of preferred food sources, potentially influenced by substrate type; ii) the site geomorphology, that could provide different dens and refuges (in terms of quantity and types of shelters) suitable for different species; iii) the colour of different substrates enhancing the mimicry of different species according to their livery and camouflage ability. Our and literature data suggest that the substrate type in rocky reefs could interact with other environmental factors (i.e., light intensity related to depth) in shaping the structure of rocky-reef assemblages.

RETRACTED: Potential effects of elevated temperature on seasonal movements in slipper lobsters, Scyllarides latus (Latreille, 1803), in the eastern Mediterranean

Retraction of: Mediterranean Marine Science http://dx.doi.org/10.12681/mms.22074, published online 13 July 2020Editor note: The authors are retracting this article.In the article, Potential effects of elevated temperature on seasonal movements in slipper lobsters, Scyllarides latus (Latreille, 1803), in the eastern Mediterranean (Vol. 21, 2020, https://doi.org/10.12681/mms.22074), authors J. Goldstein and E. Spanier have made an honest error in the inaccurate interpretation of their special scientific permit that afforded them the opportunity to collect wild-caught animals in the field and release them in their study area, in the marine reserve where this work was conducted. More specifically, the study component that refers to the ‘field tagging study’, was carried out without the full scope of permitting guidance unbeknownst to the authors. Dr. R. Yahel and E. Miller, Marine Ecologists of the Israeli National Park Authority (INPA), have pointed this out and have since requested that the article be removed given that the application of the special use permit was misinterpreted and not exercised in an appropriate manner. The authors were also not able to forward the INPA with the field’s raw data that have been lost since this field study was carried out over eight years ago. The authors were not aware of this discrepancy at the time the field study was carried out, but they have agreed to remove the article out of respect and admiration of the INPA and the continued protection and conservation of the Mediterranean slipper lobster in coastal Israeli waters. However, this action of retraction does not change the overall outcome of the paper’s finding including the study design, analyses, scientific integrity, or overall conclusions. The authors will plan on publishing the laboratory-based portion of this study as a stand-alone manuscript at a future date.

The complete mitochondrial genome of Aesop slipper lobster Scyllarides haanii (De Haan, 1841)

The complete mitochondrial genome of Scyllarides haanii from South China Sea was first determined and characterized. With a length of 15,666 bp, the circular mitogenome of S. haanii consists of 22 tRNA genes, two rRNA genes, 13 protein-coding genes (PCGs), and one control region. The nucleotide composition is significantly biased (A, G, T, and C was 32.05%, 12.45%, 33.97%, and 21.53%, respectively) with A + T contents of 66.02%. Two PCGs used an unusual initiation codon, and five PCGs were ended with an uncomplete or abnormal stop codon. One microsatellite was identified in the mitogenome located in ND4 gene. Phylogenetic analysis demonstrated that S. haanii was first clustered with Scyllarides squammosus, then together with Scyllarides latus.

Potential effects of elevated temperature on seasonal movements in slipper lobsters, Scyllarides latus (Latreille, 1803), in the eastern Mediterranean

Temperature serves a predominant motivator for movement and activity over a wide range of mobile marine ectotherms. Water temperature modulates the movements of many lobster species, which can vary widely over spatial and temporal scales. Providing insight into the thermal preferences (and refuges) that some lobsters seek remains a key tenet to our understanding of the behavioral ecology of these animals. The Mediterranean slipper lobster (Scyllarides latus) shows seasonal movements throughout most of its range and is subject to a changing thermal environment. We examined the seasonal movements of S. latus within a small marine reserve (Rosh Hanikra Marine Reserve, RHR) off the coast of Israel and tested the hypothesis that S. latus engage in increased movements when subjected to temperatures outside their range. We conducted a field survey in the RHR and tagged lobsters (n = 81, carapace length, CLavg= 88.7 ± 4.6) to investigate their activity during their putative summer movement. In the lab, we exposed a separate set of lobsters (n = 10, CLavg= 83.1 ± 6.1) to the same thermal profiles as in the field and assayed their locomotion using activity wheels. Field results revealed that lobsters tagged in shallow waters moved to deeper, cooler waters (~ 30 m) over the course of 2-2.5 months traveling an average distance of 3.4 km (range = 1-5 km). Our lab results showed that S. latus are more active at higher temperatures, but moreover, revealed that warming water temperatures elicited markedly longer movements over a similar timeframe. Combined, these findings suggest that increasing water temperatures in the eastern Mediterranean (Levant) may affect lobster movements and could alter seasonal patterns of distribution as well.

Tracking the Slipper Lobster Using Acoustic Tagging: Testbed Description

The technique of underwater acoustic localization (UAL) is widely used to track submerged targets. In the present study, we consider UAL in the specific application of locating the Mediterranean slipper lobster, Scyllarides latus (S. latus) , for the aim of continuous and long-term investigation of its movement patterns. Since visual inspections only offer a snapshot to the life of these nocturnal crustaceans, we used underwater acoustic tags and deployed the first testbed to track a community of S. latus through UAL. The testbed included 19 acoustically tagged S. latus , as well as a sensor network of four receivers that record the time-of-arrival of detected tag's emissions. The testbed operated for six months, and the data collected were analyzed offline. In this paper, we describe the design details of our testbed. We discuss the considerations in choosing both the type of acoustic tags and the structure of the testbed. We also present our algorithm to time synchronize the receivers, and the localization procedure. Our preliminary results show that, for this long-term deployment, the widely used model of clock offset for the receivers is too simplified, and that time synchronization must consider also the clock's skew. We also show that the tagged lobsters are mostly detected by fewer than three receivers, thereby making localization using traditional trilateration methods highly challenging. Finally, preliminary results for the localization of the tagged lobsters in the deployment area are presented.

Complete mitochondrial genome of blunt slipper lobsters Scyllarides squammosus (H. Milne Edwards, 1837)

The complete mitochondrial genome of Scyllarides squammosus was first determined and characterized. With a length of 15,644 bp, it consists of 22 tRNA genes, 2 rRNA genes, 13 protein-coding genes (PCGs), and 1 control region. The nucleotide composition is significantly biased with AT contents of 65.6%. Among these PCGs, five of them used an unusual initiation codon, and nine genes ended with an incomplete or abnormal stop codon. Two microsatellites were identified and located in COX3 gene and D-loop region. Phylogenetic analysis demonstrated that S. squammosus was first clustered with Scyllarides latus, which was consistent with the previous work.

Description of pereiopod setae of scyllarid lobsters, Scyllarides aequinoctialis, Scyllarides latus, and Scyllarides nodifer, with observations on the feeding during consumption of bivalves and gastropods

The morphological and behavioral aspects of slipper lobster (Scyllaridae) feeding have remained largely unexplored. Using scanning electron microscopy, the gross morphological structure of all segments of the pereiopods were described for three species of scyllarid lobsters. Five types of setae within three broad categories were found: simple (long and miniature), cuspidate (robust and conate), and teasel (a type of serrulate setae). Setae were arranged in a highly-organized, row-like pattern on the ventral and dorsal surfaces. Cuspidate setae were found on all surfaces of all segments. Simple setae were found only on the dactyl, whereas teazel setae were concentrated on the lateral-most edge of the alate carina on the merus in only one species [Scyllarides aequinoctialis (Lund, 1793)]; this species also differed from the other two [Scyllarides nodifer (Stimpson, 1866), Scyllarides latus (Latreille, 1803)] in setal patterning. All examined slipper lobsters differed in setal types and patterns from nephropid and palinurid lobsters, likely due to the more rigorous use of their pereiopods in accessing food. Feeding sequences of two of the slipper lobster species were videotaped and analyzed, and demonstrated a complex set of behaviors involving contact chemoreception by the antennules as part of an initial assessment of the food item, followed by extensive manipulation, probing, and eventual wedging behavior by the pereiopods as previously described for Scyllarides. Use of the antennules for food assessment and heavy reliance on the pereiopods, rather than the mouthparts, for food handling contrasts with nephropid and palinurid lobsters.

Winter stranding of Mediterranean slipper lobsters, Scyllarides latus

Stranding of the Mediterranean slipper lobster, Scyllarides latus, is reported for the first time for this species and in the Scyllaridae family. A total of 8 and 12 adult lobsters were found in two occasions on a sandy beach of northern Israel close to a winter seasonal shallow rocky complex habitat of this species in January 2016. The distance between the stranded lobsters was a few to about 20 m. All stranded specimens were adults with no biofouling on their exoskeleton. The absence of biofouling indicates that they were just after the presumed molting period in deeper water. Both strandings were recorded immediately following extreme storms. The maximum wave height of the storms was 9 m and the wave period 11.8 s. The estimated breaker zone started at 7.2 m deep, located more than 400 m offshore on a relatively flat, bare soft bottom substrate. It is postulated that lobsters, encountering such harsh storms on a relatively exposed terrain offshore, on their way back from their proposed deep water fall migration to the shallower winter seasonal rocky habitats, were unable to avoid the powerful drag forces. Under such circumstances their antipredator adaptations of powerful clinging to rough bottom, using their strong legs to grasp the substrate and resist being dislodged or sheltering in rocky caves and crevices, would not be effective against intense waves and currents and they were swept to shore. Damage detected on the carcasses of the stranded lobsters support this hypothesis. It is not clear whether previous similar strandings remained unnoticed or these events resulted from unique and rare coincidences of the lobsters’ location during their shoreward migration, the shelf bathymetry and the timing and positions of extreme storms.

Into a rhythm: diel activity patterns and behaviour in Mediterranean slipper lobsters, Scyllarides latus

AbstractAlthough the natural history for Mediterranean slipper lobsters (Scyllarides latus) is well established, there exists a disproportionate lack of important biological and physiological data to verify many key traits, including to what extent endogenous rhythms modulate aspects of their behaviour. Although Scyllarids appear nocturnally active, few studies exist that quantify this tendency. Our overall objective was to test the hypothesis that adult slipper lobsters are nocturnal and to determine if their diel activity rhythms are under the influence of an endogenous circadian clock. In the laboratory, we exposed a total of 16 animals (CLavg = 92.6 ± 6.6 mm; CL, carapace length) to a 12 : 12 light : dark (LD) cycle for 7–10 d, followed by ***constant dark (DD) for 15–20 d. Activity was assessed using a combination of time-lapse video and accelerometers. Of a total of 16 lobsters, we analysed data from 15 (one mortality). All 15 lobsters were evaluated using video. Thirteen of these lobsters were also evaluated using accelerometers. All lobsters were more active during night-time than during daytime and synchronized their activity to the LD cycle, expressing a diel activity pattern (τ = 24.04 ± 0.13 h). In DD, lobsters maintained a circadian rhythm with a τ of 23.87 ± 0.07 h. These findings may provide insight into the behaviour of these animals in their natural habitat and help explain their ability to anticipate dawn and dusk.

Abundance and distribution of scyllarid phyllosoma larvae (Decapoda: Scyllaridae) in the Balearic Sea (Western Mediterranean)

The distribution, abundance, and interannual variation of scyllarid phyllosoma larvae were studied in waters of the Balearic Sea (Western Mediterranean) from plankton samples collected between 2001 and 2005. Over the study period, 342 phyllosomas were collected, all belonging to Scyllaridae. Scyllarus arctus (Linnaeus, 1758) was the most abundant (89%), with representation of all developmental stages (I-X), except stage IX, plus two nistos. Scyllarus pygmaeus (Bate, 1888) phyllosoma included middle stages (IV-VII) and two final stages X. Finally, a stage II phyllosoma of Scyllarides latus (Latreille, 1802) was recorded for the first time in the Western Mediterranean. The majority of the phyllosomas were early stage S. arctus found in near shore stations, while advanced stages were common farther away from the coast, especially to the south of the Balearic Sea. That was also the case of S. pygmaeus, most of which stage V, observed to the southwest of the archipelago. Phyllosomas were scarce in low salinity (S<37.2) water masses of recent Atlantic origin, and interannual differences in distribution reflected the intrusions of low salinity Atlantic water from the South.

Findings of Phyllosoma Larvae and Nistos of the Family Scyllaridae (Crustacea, Decapoda) in the Southern Mediterranean Sea

The rare findings of specimens in larval or post-larval stages (6 phyllosomas and 7 nistos/early juveniles) belonging to the family Scyllaridae are reported for the waters around Sicily. Some were stranded on different winter occasions near the Strait of Messina (north-eastern Sicily), while others were collected during experimental trawl surveys carried out in the Sicilian Channel, at depths up to 450 m. All phyllosoma instars were in advanced stages of development; however, the absence of complete morphological references on the larval characteristics of the family Scyllaridae, necessary for distinguishing the different genera (Scyllarus and Scyllarides, small or large slipper lobsters, or the extremely rare Acantharctus) and species inhabiting the Mediterranean, did not allow to attribute the phyllosomas to a specific taxon. On the contrary, apart from one nisto without apparent lobes (maybe belonging to the species Scyllarides latus), nistos/early juveniles could be classified at generic level on the basis of similarities with the morphology of adult antennae, as pertaining to the genus Scyllarus, but the characters of juveniles are in general ineffective to discriminate between Scyllarus arctus and Scyllarus pygmaeus (the only two known Central Mediterranean species); in fact, the small size and the depth at which they settled suggested that some may belong to the smaller, deeper species Scyllarus pygmaeus.

Larval stages of crustacean species of interest for conservation and fishing exploitation in the western Mediterranean

Decapod crustaceans are the main target species of deep water bottom trawl fisheries in the western Mediterranean. Despite their importance for fisheries and conservation, little is known about their larval development, especially in the case of deep water species. In this paper we present new information on the occurrence and morphology of larval stages for some species of commercial interest based on samples collected off the Balearic Islands. Mesozooplankton sampling was carried out using depth-stratified sampling devices at two stations located on the continental shelf break and middle slope, in the northwest and south of Mallorca in late autumn 2009 and summer 2010. We describe in detail the second mysis stage of the red shrimp Aristeus antennatus , not previously known, and the first larval stage of the slipper lobster Scyllarides latus , poorly described almost a hundred years ago. We also report the second finding of larvae of the spider crab Maja squinado and the first capture from the field of larval stages of the rose shrimp Parapenaeus longirostris and slipper lobster in the Mediterranean.

DNA barcoding commercially important aquatic invertebrates of Turkey

DNA barcoding was used in order to identify aquatic invertebrates sampled from fisheries bycatch and discards. A total of 440 unique cytochrome c oxidase sub unit I (COI) barcodes were generated for 22 species from three important phyla (Arthropoda, Cnidaria, and Mollusca). All the species were sequenced and submitted to GenBank and Barcode of Life Database (BOLD) databases using 654 bp-long fragment of mitochondrial COI gene. Two of them (Pontastacus leptodactylus and Rapana bezoar) were first records of the species for the BOLD database and six of them (Carcinus aestuarii, Loligo vulgaris, Melicertus kerathurus, Nephrops norvegicus, Scyllarides latus, and Scyllarus arctus) were first standard (>648 bp) COI barcode records for the GenBank database. COI barcodes were analyzed for nucleotide composition, nucleotide pair frequencies, and Kimura's two-parameter genetic distance. Mean genetic distance among species was found increasing at higher taxonomic levels. Neighbor-joining trees generated were congruent with morphometric-based taxonomic classification. Findings of this study clearly demonstrate that DNA barcodes could be used as an efficient molecular tool in identification of not only target species from fisheries but also bycatch and discard species, and so it could provide us leverage for a better understanding in monitoring and management of fisheries and biodiversity.

First record of an early benthic juvenile likely to be that of the Mediterranean slipper lobster, Scyllarides latus (Latreille, 1802)

To date no nisto and/or live juvenile of the Mediterranean slipper lobster, Scyllarides latus (Latreille, 1802), has been found despite intensive sampling efforts. In the early 1900s, a tiny preserved specimen, almost certainly of this species, with carapace length of 11.7 mm, sampled in Reggio Calabria, southern Italy, was captured and deposited in the Zoological Museum of Turin. This early scyllarid juvenile, likely a recent benthic recruit, varies somewhat from the adult form of the local Mediterranean species, S. latus, by having a carapace width that is greater than the carapace length and by having more prominent tubercles than adults. These same features also have been noted in nistos of a few other non-Mediterranean Scyllarides species, especially those of S. nodifer (Stimpson, 1866). Although the collection information for this specimen was incomplete, additional data on habitats of sub-adults of S. latus enable the construction of a hypothetical recruitment scenario. It is likely that S. latus larvae drift large distances for many months in the pelagic before settling as nistos in deeper water where they are possibly more protected against predators and develop to small juveniles before returning to the shallower adult grounds as migrating larger juveniles or sub-adults.

Panmixia in the endangered slipper lobster Scyllarides latus from the northeastern Atlantic and western Mediterranean

In the marine realm, it is important to understand the connectivity and population dynamics of commercially exploited species; this information promotes sustainable fishing practices. The large slipper lobster, Scyllarides latus (Latreille, 1803), is a commercially valuable crustacean that has been over-exploited in many areas throughout its distribution range in the northeastern (hereafter NE) Atlantic and the Mediterranean. Here, we report the first molecular population genetic study of S. latus based on 9 nuclear microsatellite loci. A total of 128 specimens of S. latus were collected in the Western Mediterranean (2 locations) and four regions (13 locations) in the NE Atlantic, including Southern Portugal and the Macaronesian archipelagos of Azores, Canary Islands and Cape Verde. Maximum number of alleles per locus ranged from 4 to 14, and observed heterozygosity per locus ranged from 0.143 to 0.795 (0.539 ± 0.087, mean ± SE). Pairwise region estimates of FST, RST and Dest were very low (<0.040) and not significant in all comparisons. Bayesian clustering analysis also suggested homogeneity in S. latus across all regions. The Almeria-Oran front, an important biogeographic boundary between the Atlantic and Mediterranean basins, was not found to have a significant impact on the genetic structuring of S. latus. Overall, all of our analyses of genetic differentiation and migration suggested panmixia in S. latus across its distributional range. Such pattern is likely to result from its high fecundity and long-lived pelagic larva, which can promote high levels of connectivity between geographically distant populations. Future conservation strategies should manage all S. latus populations jointly (one stock).

Mitogenomic analysis of decapod crustacean phylogeny corroborates traditional views on their relationships

Phylogenetic relationships within decapod crustaceans are highly controversial. Even recent analyses based on molecular datasets have shown largely contradictory results. Previous studies using mitochondrial genomes are promising but suffer from a poor and unbalanced taxon sampling. To fill these gaps we sequenced the (nearly) complete mitochondrial genomes of 13 decapod species: Stenopus hispidus, Polycheles typhlops, Panulirus versicolor, Scyllarides latus, Enoplometopus occidentalis, Homarus gammarus, Procambarus fallax f. virginalis, Upogebia major, Neaxius acanthus, Calocaris macandreae, Corallianassa coutierei, Cryptolithodes sitchensis, Neopetrolisthes maculatus, and add that of Dromia personata. Our new data allow for comprehensive analyses of decapod phylogeny using the mitochondrial genomes of 50 species covering all major taxa of the Decapoda. Five species of Stomatopoda and one species of Euphausiacea serve as outgroups. Most of our analyses using Maximum Likelihood (ML) and Bayesian inference (BI) of nucleotide and amino acid datasets revealed congruent topologies for higher level decapod relationships: (((((((Anomala, Brachyura), Thalassinida: Gebiidea), Thalassinida: Axiidea), (Astacidea, Polychelida), Achelata), Stenopodidea), Caridea), Dendrobranchiata). This result corroborates several traditional morphological views and adds new perspectives. In particular, the position of Polychelida is surprising. Nevertheless, some problems can be identified. In a minority of analyses the basal branching of Reptantia is not fully resolved, Thalassinida are monophyletic; Polychelida are the sister group to Achelata, and Stenopodidea are resolved as sister group to Caridea. Despite this and although some nodal supports are low in our phylogenetic trees, we think that the largely stable topology of the trees regardless of different types of analyses suggests that mitochondrial genomes show good potential to resolve the relationship within Decapoda.

Oxygen-binding modulation of hemocyanin from the slipper lobster Scyllarides latus

The oxygen-binding properties of hexameric hemocyanin (Hc) from Scyllarides latus were investigated with respect to pH, temperature, and modulating effect exerted by calcium, lactate, and urate. The oxygen affinity decreased at higher temperature, was slightly affected by pH, and was insensitive to lactate. Nevertheless, urate markedly increased Hc–oxygen affinity and its temperature sensitivity, acting as the physiological major positive effector: four urate sites per hexamer with an overall affinity constant of 1×10 4 M −1 were found and the exothermic contribution of their binding was found to be about 30 kJ mol −1. Calcium ions largely influenced oxygen affinity: their effect, which has an opposite sign at low (0–1 mM) and high (0.1–1 M) concentration ranges, indicates the presence of two independent types of binding sites with high and low affinity, respectively; however, only the former ones seem to be operative in vivo because, at physiological calcium concentrations, they are already saturated and the oxygen affinity is reduced.

Morphometric aspects of Scyllarides latus

The slipper lobster, Scyllarides latus (Latreille, 1803), is the only representative species of the genusScyllarides in the Mediterranean Sea. In this study, we examined some biological aspects of this species sampled in the Straits of Messina. The specimens were sexed, measured and weighed. The relationships between body measurements (length and width of the carapace, antennal length) and length-weight relationship were calculated. Furthermore, the correlation matrix (Pearson’s coefficient) was calculated. Two hundred specimens were collected, ranging in size from 81 to 305 mm in total length, and between 21 and 1490 g in weight. A rare juvenile of 39 mm CL was recorded. A sex ratio of 1:1 was found. The carapace length – weight relationship was almost isometric. The wide size range sampled and the presence of a juvenile, indicate an interesting habitat for studying the presence and growth of Scyllarides latus in the Straits of Messina.