Sepia Officinalis Research Articles

KARAKTERISTIK DAN NILAI SUN PROTECTING FACTOR (SPF) KITOSAN DARI TULANG SOTONG (Sephia officinalis)

Cuttlefish (sepia officinalis) have internal shells commonly called cuttlebones which produce more chitin than shrimp shells and crab skins. The purpose of this study was to determine the characteristics of chitosan from cuttlebone including the degree of deacetylation, water content, solubility, organoleptic test (color, odor, texture) as well as testing the value of chitosan protecting the sun protection factor. Chitosan is made in 3 stages, namely deproteination, demineralization, and deacetylation. Deproteination with 4% NaOH at 100 ° C for 60 minutes. Demineralization at room temperature using 1M HCl solution for 120 minutes. Deacetylation using 50% NaOH concentration at 100 ° C for 60 minutes. Chitosan characterization includes the degree of deacetylation, moisture content, solubility, organoleptic test (color, odor, texture). Testing the value of sun protection factor using a UV-VIS spectrophotometer read at wavelengths from 290 to 320 nm. Characteristics of chitosan produced according to chitosan standards used in industry with a deacetylation rate of 71%, yield 31%, moisture content of 0.93%, soluble in acetic acid2% solution, white odorless and powdery. Chitosan with a concentration of 3% gives the value of sun protecting factor 9 as a potential sunscreen that provides maximum protection power.

Mercury in the tissues of five cephalopods species: First data on the nervous system

Mercury (Hg), one of the elements most toxic to biota, accumulates within organisms throughout their lifespan and biomagnifies along trophic chain. Due to their key role in marine systems, cephalopods constitute a major vector of Hg in predators. Further, they grow rapidly and display complex behaviours, which can be altered by neurotoxic Hg. This study investigated Hg concentrations within 81 cephalopod specimens sampled in the Bay of Biscay, which belonged to five species: Eledone cirrhosa, Sepia officinalis, Loligo vulgaris, Todaropsis eblanae and Illex coindetii. Hg concentrations were measured in the digestive gland, the mantle muscle and the optic lobes of the brain. The digestive gland and the mantle were tissues with the most concentrated Hg among all species considered (up to 1.50 μg.g−1 dw), except E. cirrhosa. This benthic cephalopod had 1.3-fold higher Hg concentrations in the brain (up to 1.89 μg.g−1 dw) than in the mantle, while other species had 2-fold lower concentrations of Hg in the brain than in the mantle. Brain-Hg concentrations can be predicted from muscle-Hg concentrations for a given species, which facilitates the assessment of Hg toxicokinetics in cephalopods. In the most contaminated E. cirrhosa individual, the chemical form of Hg in its digestive gland, mantle muscle and optic lobes, was determined using High energy-Resolution X-ray Absorption Near Edge Structure (HR XANES) spectroscopy. In the digestive gland, 33 ± 11% of total Hg was inorganic Hg speciated as a dicysteinate complex (Hg(Cys)2), which suggested that the demethylation of dietary MeHg occurs in this organ. All Hg found in the mantle muscle and the optic lobes is methylated and bound to one cysteinyl group (MeHgCys complex), which implies that dietary MeHg is distributed to these tissues via the bloodstream. These results raised the questions regarding interspecific differences observed regarding Hg brain concentrations and the possible effect of Hg on cephalopod functional brain plasticity and behaviour.

Feeding Habits and Reproduction Period of Sepia officinalis (Linnaeus, 1758) Captured from East Mediterranean Sea

Feeding Habits and Reproduction Period of Sepia officinalis (Linnaeus, 1758) Captured from East Mediterranean Sea

Seasonal metabolic and oxidative stress responses of commercially important invertebrate species—correlation with their habitat

Habitat conditions play a crucial role in food acquisition and the energetic and physiological performance of marine organisms during seasonal changes. However, across a wide distribution, populations of the same species might face physiological constraints driven by the oceanographic and climatological characteristics of their habitats. In the context of climate change, biochemical and metabolic data may be important in identifying marine areas in which inhabiting organisms are more or less physiologically constrained. As a first step in identifying such marine areas on the Greek coast, we studied the seasonal metabolic and antioxidant responses of blue crab Callinectes sapidus, cuttlefish Sepia officinalis, sea cucumber Holothuria tubulosa and clam Venus verrucosa, collected from 3 different Greek gulfs: Thermaikos, Pagasitikos and Vistonikos. Seasonal analysis of metabolic responses was based on the activity of the following intermediary metabolic enzymes: lactate dehydrogenase (L-LDH), octopine dehydrogenase (ODH), β-hydroxyacyl-CoA dehydrogenase (HOAD) and citrate synthase (CS). Antioxidant responses were based on the activities of the following enzymes: superoxide dismutase (SOD), glutathione reductase (GR) and catalase, and on lipid peroxidation estimation. The blue crab and clam exhibited the most significant seasonal changes compared to the sea cucumber and cuttlefish, which exhibited no changes. The intermediary metabolism enzymatic activity of blue crab and clam decreased and antioxidant enzymatic activity increased during summer. Higher activity levels for all examined species were observed in Pagasitikos and lower levels in Vistonikos Gulf, indicating corresponding oxidative stress. These results are correlated with the spatial oceanographic conditions of the habitats and are discussed based on future projections of global warming in the Mediterranean Sea.

Investigation of β-chitin extracted from cuttlefish: comparison with squid β-chitin

β-chitins are extracted from two different parts of cuttlefish (Sepia officinalis officinalis) bone; the shell and the thin layer. They are then subjected to N-deacetylation reactions to prepare chitosans using the Broussignac or the Kurita process. The physicochemical characteristics of chitins and chitosans are compared to those obtained in the case of squid (Loligo vulgaris) β-chitin. In this work, the role of the source in determining the reaction behavior, during the extraction of chitin and the preparation of chitosan, is confirmed, although it is a β-chitin of two taxonomically close species. In particular, we show that the differences observed can be related to the differences in molar masses of the starting chitins, their crystallinity index and the rates of molecular degradation which accompany the N-deacetylation reactions. Finally, it was demonstrated that the huge quantities of bones rejected each year by the cuttlefish processing units from Dakhla city, alone, can be valorized by the production of about 77 tons of β-chitin that can be transformed into 60 tons of chitosan (presenting low degree of acetylation and molar masses ranging from 78,000 to 340,000 g/mol).

Diversity of Light Sensing Molecules and Their Expression During the Embryogenesis of the Cuttlefish (Sepia officinalis).

Eyes morphologies may differ but those differences are not reflected at the molecular level. Indeed, the ability to perceive light is thought to come from the same conserved gene families: opsins and cryptochromes. Even though cuttlefish (Cephalopoda) are known for their visually guided behaviors, there is a lack of data about the different opsins and cryptochromes orthologs represented in the genome and their expressions. Here we studied the evolutionary history of opsins, cryptochromes but also visual arrestins in molluscs with an emphasis on cephalopods. We identified 6 opsins, 2 cryptochromes and 1 visual arrestin in Sepia officinalis and we showed these families undergo several duplication events in Mollusca: one duplication in the arrestin family and two in the opsin family. In cuttlefish, we studied the temporal expression of these genes in the eyes of embryos from stage 23 to hatching and their expression in two extraocular tissues, skin and central nervous system (CNS = brain + optic lobes). We showed in embryos that some of these genes (Sof_CRY6, Sof_reti-1, Sof_reti-2, Sof_r-opsin1 and Sof_v-arr) are expressed in the eyes and not in the skin or CNS. By looking at a juvenile and an adult S. officinalis, it seems that some of these genes (Sof_r-opsin1 and Sof_reti1) are used for light detection in these extraocular tissues but that they set-up later in development than in the eyes. We also showed that their expression (except for Sof_CRY6) undergoes an increase in the eyes from stage 25 to 28 thus confirming their role in the ability of the cuttlefish embryos to perceive light through the egg capsule. This study raises the question of the role of Sof_CRY6 in the developing eyes in cuttlefish embryos and the role and localization of xenopsins and r-opsin2. Consequently, the diversity of molecular actors involved in light detection both in the eyes and extraocular tissues is higher than previously known. These results open the way for studying new molecules such as those of the signal transduction cascade.

Status of Sepia officinalis and 19 Main Fisheries Species Caught from Southeast Mediterranean Sea, North Sinai, Egypt.

Status of Sepia officinalis and 19 Main Fisheries Species Caught from Southeast Mediterranean Sea, North Sinai, Egypt.

Glial cells in the posterior sub-esophageal mass of the brain in Sepia officinalis (Linnaeus, 1758) (decapodiformes-sepiida): ultrastructure and cytochemical studies.

Electron microscopy revealed that glial cells in the posterior sub-esophageal mass of the brain in Sepia officinalis had a well-developed rough endoplasmic reticulum formed by long coverslips with rectilinear or curvilinear arrangements. The coverslips appeared dilated and have a large amount of adhered polysomes. Vesicular lamellae coexisted with the elongated lamellae of RER and dictyosomes of Golgi apparatus. Endocytosis was evidenced through the pale vesicles which were appeared next to the apical border of microvilli in some glial cells. Sub-cellular features of endocytosis, predominantly the fluid phase, were observed in the apical glial cell cytoplasm. Glial cells were related to phagocytosis of apoptotic neurons, endocytosis, pinocytosis and adsorption. These functions were proposed based on their ultrastructure characteristics and a significant number of vesicles with different shapes (oval to polygonal), sizes 0.052-0.67µm and contents. Glycogen, MPS and lipid were detected in the glial cells. Alkaline phosphatase was not observed, while an activity of acid phosphatase was bound to lysosomes. ATPases were present in the glial cells along the lateral and basal plasma lemma as well as on the membranes of cell organelles. Unspecific esterase was clearly recognizable by electron microscopy. The monoamine and cytochrome oxidase activities were demonstrated, while the succinate dehydrogenase showed a weak enzyme activity.

In-Depth In Silico Search for Cuttlefish (Sepia officinalis) Antimicrobial Peptides Following Bacterial Challenge of Haemocytes

Cuttlefish (Sepia officinalis) haemocytes are potential sources of antimicrobial peptides (AMPs). To study the immune response to Vibrio splendidus and identify new AMPs, an original approach was developed based on a differential transcriptomic study and an in-depth in silico analysis using multiple tools. Two de novo transcriptomes were retrieved from cuttlefish haemocytes following challenge by V. splendidus or not. A first analysis of the annotated transcripts revealed the presence of Toll/NF-κB pathway members, including newly identified factors such as So-TLR-h, So-IKK-h and So-Rel/NF-κB-h. Out of the eight Toll/NF-κB pathway members, seven were found up-regulated following V. splendidus challenge. Besides, immune factors involved in the immune response were also identified and up-regulated. However, no AMP was identified based on annotation or conserved pattern searches. We therefore performed an in-depth in silico analysis of unannotated transcripts based on differential expression and sequence characteristics, using several tools available like PepTraq, a homemade software program. Finally, five AMP candidates were synthesized. Among them, NF19, AV19 and GK28 displayed antibacterial activity against Gram-negative bacteria. Each peptide had a different spectrum of activity, notably against Vibrio species. GK28—the most active peptide—was not haemolytic, whereas NF19 and AV19 were haemolytic at concentrations between 50 and 100 µM, 5 to 10 times higher than their minimum inhibitory concentration.

Effects of temperature on the rate of embryonic development of cephalopods in the light of thermal time applied to aquaculture

AbstractThe temporal description of the embryonic development in ectothermic animals and the speed of development depends on environmental temperature. The concept of thermal time helps in solving this problem by making it possible to define a linear model of development linking developmental rate and temperature. The model has been scarcely applied to cephalopods in spite of being useful for programming embryonic development and hatching events. The potential application of the linear model of development would have particular interest in the case of emerging species for aquaculture such as Octopus vulgaris or Sepia officinalis. Therefore, the main goal of this work is to review the effect of temperature on the rate of embryonic development in cephalopods in relation to the linear model of development and to discuss its potential applications and limitations to cephalopod aquaculture. As a result, a good fitting of the model has been proven not only for the total time of development, but also for the time of the organogenesis phase, in nine species of cephalopods. Usually, threshold temperatures for different developmental phases, pre‐organogenesis, organogenesis and growth, are the same. In addition, the potential use of anisothermic protocols for egg incubation, as well as the problems connected with the asynchronicity of egg laying within a single spawning are also discussed. In consequence, the linear model of development seems to be useful for basic and applied research on cephalopod embryonic development and particularly for the advancement of cephalopod aquaculture.

Microplastics presence in cultured and wild-caught cuttlefish, Sepia officinalis

Amongst cephalopods microplastics have been reported only in jumbo squid gut. We investigated microplastics in the digestive system of wild cuttlefish (Sepia officinalis) as they are predators and prey and compared the stomach, caecum/intestine and digestive gland (DG) of wild and cultured animals, exposed to seawater from a comparable source. Fibers were the most common type (≈90% of total count) but were ≈2× higher in relation to body weight in wild vs. cultured animals. Fibers were transported to the DG where the count was ≈2× higher /g in wild (median 1.85 fibers/g) vs. cultured. In wild-caught animals the DG was the predominant location but in cultured animals the fibers were more evenly distributed in the digestive tract. The potential impact of microplastics on health of cuttlefish is discussed. Cuttlefish represent a previously unrecognized source of microplastic trophic transfer to fish and finding fibers in cultured animals has implications for aquaculture.

Feeding ecology of the highly threatened common bottlenose dolphin of the Gulf of Ambracia, Greece, through stable isotope analysis

AbstractThe Gulf of Ambracia, in northwestern Greece, hosts a highly threatened community of about 150 common bottlenose dolphins (Tursiops truncatus). Until now, information on their feeding habits was derived exclusively from fish scale samples collected during surface‐feeding events targeting small schooling epipelagic fish. The aim of this study was to determine the diet of bottlenose dolphins living in the Gulf of Ambracia through the application of Bayesian isotopic mixing models. Skin biopsy samples of 16 dolphins were analyzed and no difference related to sex or age‐class was found in δ13C and δ15N values. Results suggested that the dolphin diet was mainly based on Trachurus trachurus, species belonging to the family Sparidae: Diplodus annularis, Lithognathus mormyrus, and Sepia officinalis, which represented together about 42% ± 15% of the biomass ingested, followed by species belonging to the order Clupeiformes (Engraulis encrasicolus, Sardinella aurita, and Sardina pilchardus) and the genus Gobius (37% ± 17%). A better understanding of the feeding habits of these dolphins sheds light on the feeding ecology of this highly threatened population by, for instance, evidencing interactions with artisanal fisheries sharing the same target species, and is key for identifying adequate management measures consistent with an ecosystem‐based approach.

Seasonal cellular stress responses of commercially important invertebrates at different habitats of the North Aegean Sea

In many aquatic species, the negative effect of temperature variations has a significant impact on physiological performance since beyond Tp (upper pejus) and Tc (critical temperatures), according to the oxygen- and capacity-limited thermal tolerance (OCLTT), transition to hypoxemia and mitochondrial metabolism triggers the increase in reactive oxygen species (ROS) production. However, climate change may have different spatial impact, and as a result, areas with more favorable climatic conditions (refugia) can be identified. The aim of the present study, based on cellular stress responses, is the demarcation of these areas and the preservation of commercially important marine species. Under this prism, individuals of the species Callinectes sapidus (blue crab), Sepia officinalis (common cuttlefish), Holothuria tubulosa (sea cucumber) and Venus verrucosa (clam) from Thermaikos, Pagasitikos and Vistonikos gulf were collected seasonally. The results showed an increase in the levels of several stress indicators exhibiting the triggering of Heat Shock Response, MAPK activation, apoptotic phenomena and increased ubiquitilination during the summer sampling in relation to the spring and autumn samplings concerning blue crab and clam, while no changes were observed for common cuttlefish and sea cucumber. It seems that these cellular responses consist a cytoprotective mechanism against environmental thermal stress. Regarding collection sites, for all examined species, higher cellular stress levels were observed in Pagasitikos, and lower in Vistonikos gulf. This analysis of biochemical and molecular markers is expected to provide a clearer picture for the definition of “refugia” for the above species.

Evidence of Sleep Cycle Analogous to Vertebrate SWS/REM Alternation in the Octopus

The combination of body quiescence and skin pattern changes displayed periodically by Sepia officinalis, as well as the high threshold for arousal upon stimulation and increased brain activity in quiescent Octopus vulgaris, suggest the existence of a state akin to rapid-eye-movement sleep (REM) in cephalopods. Would be possible that cephalopods, as amniotes, sleep through the alternation of distinct quiescent states, analogous to slow-wave sleep (SWS) and REM? To investigate this possibility, we video-recorded 4 adult specimens of Octopus insularis and quantified in detail their behavioral states and transitions. We also performed sensory stimulation to measure reaction times across all behavioral states. Two distinct quiescent states occurred in tandem, both quite unresponsive to stimulation (median reaction time: 50 s). The first state was SWS-like, characterized by uniformly pale skin, closed pupils, and long episode durations (median 415.2 s). The second state was REM-like, characterized by dynamic skin patterns, rapid eye movements and short episode durations (median 40.8 s). The REM-like state was periodic (60% of all recurrences between 26.85-39.15 min) and occurred mostly after the SWS-like state (82% of all transitions). These observations support the existence in cephalopods of an ultradian sleep cycle analogous to the SWS/REM alternation.

Pots vs trammel nets: a catch comparison study in a Mediterranean small-scale fishery.

Passive bottom-set nets are the most widely used fishing gears in Mediterranean small-scale fisheries (SSFs). Trammel nets, in particular, have key advantages such as their ease of use and handling and high capture efficiency for numerous commercial species. However, they entail high discard rates (5–44% of the total catch) connected to high mortality, thus exerting an adverse impact on benthic communities, besides catching individuals of commercial species under the minimum conservation reference size (MCRS) and specimens of protected species. Fish pots are seen as alternative and a more sustainable gear type that allow reducing discards in SSFs. In this study, a collapsible pot was tested at three coastal sites in the north-western Adriatic Sea (GFCM GSA 17) to compare its catch efficiency with that of the local traditional trammel nets. Data analysis demonstrated a similar catch efficiency for the commercial species, both among sites and as a whole. Moreover, the trammel net caught a larger amount of discards, both in terms of species number and of CPUEW. The catch comparison study involved the two most abundant landed species, common cuttlefish Sepia officinalis and annular sea bream Diplodus annularis. The pots were more effective for S. officinalis, whereas the trammel net was more effective for the shorter length classes for D. annularis, which were mostly under the MCRS (12 cm). The innovative pots could provide a valuable alternative to the trammel nets traditionally used in the Adriatic Sea, at least in certain areas and periods. Their main advantages include that they do not require a different rigging and they can be used without bait, while their foldable design allows large numbers to be easily loaded on board SSF vessels. The results of this pilot study indicate that pots can achieve the objectives of reducing discards and bycatch in SSFs without penalizing the catch of commercial species.

Neurally underdeveloped cuttlefish newborns exhibit social learning.

Learning can occur through self-experience with the environment, or through the observation of others. The latter allows for adaptive behaviour without trial-and-error, thus maximizing individual fitness. Perhaps given their mostly solitary lifestyle, cuttlefish have seldomly been tested under observational learning scenarios. Here we used a multi-treatment design to disentangle if and how neurally immature cuttlefish Sepia officinalis hatchlings (up to 5days) incorporate social information into their decision-making, when performing a task where inhibition of predatory behaviour is learned. In the classical social learning treatment using pre-trained demonstrators, observers did not register any predatory behaviour. In the inhibition by social learning treatment, using naïve (or sham) demonstrators, more observers than demonstrators learned the task, while also reaching learning criterion in fewer trials, and performing less number of attacks per trial. Moreover, the performance of demonstrator-observer pairs was highly correlated, indicating that the mere presence of conspecifics did not explain our results by itself. Additionally, observers always reported higher latency time to attack during trials, a trend that was reversed in the positive controls. Lastly, pre-exposure to the stimulus did not improve learning rates. Our findings reveal the vicarious capacity of these invertebrate newborns to learn modulation (inhibition) of predatory behaviour, potentially through emulation (i.e. affordance learning). Despite ongoing changes on neural organization during early ontogeny, cognitively demanding forms of learning are already present in cuttlefish newborns, facilitating behavioural adaptation at a critical life stage, and potentially improving individual fitness in the environment.

Natural geochemical markers reveal environmental history and population connectivity of common cuttlefish in the Atlantic Ocean and Mediterranean Sea

Natural markers (δ13C and δ18O stable isotopes) in the cuttlebones of the European common cuttlefish (Sepia officinalis) were determined for individuals collected across a substantial portion of their range in the Northeast Atlantic Ocean (NEAO) and Mediterranean Sea. Cuttlebone δ13C and δ18O were quantified for core and edge material to characterize geochemical signatures associated with early (juvenile) and recent (sub-adult/adult) life-history periods, respectively. Regional shifts in cuttlebone δ13C and δ18O values were detected across the 12 sites investigated. Individuals collected from sites in the NEAO displayed more enriched δ13C and δ18O values relative to sites in the Mediterranean Sea, with the latter also showing salient differences in both markers among western, central and eastern collection areas. Classification success based on cuttlebone δ13C and δ18O values to four geographical regions (NEAO, western, central and eastern Mediterranean Sea) was relatively high, suggesting that environmental conditions in each region were distinct and produced area-specific geochemical signatures on the cuttlebones of S. officinalis. A modified δ13C and δ18O baseline was developed from sites proximal to the Strait of Gibraltar in both the NEAO and Mediterranean Sea to assess potential mixing through this corridor. Nearly, all (95%) of δ13C and δ18O signatures of S. officinalis collected in the area of the NEAO closest to the Strait of Gibraltar (Gulf of Cadiz) matched the signatures of specimens collected in the western Mediterranean, signifying potential movement and mixing of individuals through this passageway. This study extends the current application of these geochemical markers for assessing the natal origin and population connectivity of this species and potentially other taxa that inhabit this geographical area.

Cuttlefish Buoyancy in Response to Food Availability and Ocean Acidification.

Carbon dioxide concentration in the atmosphere is expected to continue rising by 2100, leading to a decrease in ocean pH in a process known as ocean acidification (OA). OA can have a direct impact on calcifying organisms, including on the cuttlebone of the common cuttlefish Sepia officinalis. Moreover, nutritional status has also been shown to affect the cuttlebone structure and potentially affect buoyancy. Here, we aimed to understand the combined effects of OA (980 μatm CO2) and food availability (fed vs. non-fed) on the buoyancy of cuttlefish newborns and respective cuttlebone weight/area ratio (as a proxy for calcification). Our results indicate that while OA elicited negative effects on hatching success, it did not negatively affect the cuttlebone weight/area ratio of the hatchlings—OA led to an increase in cuttlebone weight/area ratio of fed newborns (but not in unfed individuals). The proportion of “floating” (linked to buoyancy control loss) newborns was greatest under starvation, regardless of the CO2 treatment, and was associated with a drop in cuttlebone weight/area ratio. Besides showing that cuttlefish buoyancy is unequivocally affected by starvation, here, we also highlight the importance of nutritional condition to assess calcifying organisms’ responses to ocean acidification.

Embracing Their Prey at That Dark Hour: Common Cuttlefish (Sepia officinalis) Can Hunt in Nighttime Light Conditions.

Cuttlefish are highly efficient predators, which strongly rely on their anterior binocular visual field for hunting and prey capture. Their complex eyes possess adaptations for low light conditions. Recently, it was discovered that they display camouflaging behavior at night, perhaps to avoid detection by predators, or to increase their nighttime hunting success. This raises the question whether cuttlefish are capable of foraging during nighttime. In the present study, prey capture of the common cuttlefish (Sepia officinalis) was filmed with a high-speed video camera in different light conditions. Experiments were performed in daylight and with near-infrared light sources in two simulated nightlight conditions, as well as in darkness. The body of the common cuttlefish maintained a velocity of less than 0.1 m/s during prey capture, while the tentacles during the seizing phase reached velocities of up to 2.5 m/s and accelerations reached more than 450 m/s2 for single individuals. There was no significant difference between the day and nighttime trials, respectively. In complete darkness, the common cuttlefish was unable to catch any prey. Our results show that the common cuttlefish are capable of catching prey during day- and nighttime light conditions. The common cuttlefish employ similar sensory motor systems and prey capturing techniques during both day- and nighttime conditions.

Length-Weight Relationships of 31 Fish and Invertebrate Species in the Northern Aegean Sea (Eastern Mediterranean Sea)

The purpose of this study was to examine the length-weight relationships (LWR) of fish and invertebrate species exploited by the small-scale coastal fleet in the northern Aegean Sea (eastern Mediterranean Sea). Length and weight measurements were collected during experimental trials carried out seasonally from April 2016 to February 2017. A total of 4358 individuals from 31 species (28 fishes, 2 crustaceans and 1 cephalopod) representing 21 families were collected. With the exception of brown comber (Serranus hepatus) and rough ray (Raja radula), all LWR slopes fall within the 2.5 to 3.5 range. The median b value for fishes was 3.11 and 50% of the b values ranged between 3.04 and 3.24. Somatic growth was isometric for 14 species, hyperallometric for 12 species, while only 5 species grew hypoallometrically. This is the first reference on LWR for sand sole (Pegusa lascaris) in the eastern Mediterranean Sea, while for snake blenny (Ophidion barbatum), common cuttlefish (Sepia officinalis) and deep-water rose shrimp (Parapenaeus longirostris) it is the first LWR in Greek waters.