Response of diademed sifaka (Propithecus diadema) to fosa (Cryptoprocta ferox) predation in the Betampona Strict Nature Reserve, Madagascar.

Large-bodied mammals living in fragmented habitats are at higher risk of extinction, and such risk can be influenced by ecological factors such as predator-prey system dynamics. These dynamics can be particularly complex for conservation management when one endangered species preys on another endangered species in an isolated or poor-quality habitat. Here we describe predation events observed over 19 months that involved two threatened species: the largest carnivore in Madagascar, the fosa (Cryptoprocta ferox), and three groups of diademed sifaka (Propithecus diadema) in the Betampona Strict Nature Reserve. This site is a 22 km2 low-altitude rainforest that is surrounded by agricultural land and isolated from larger forest corridors. We aim to (1) assess the behavioral changes of P. diadema in response to fosa attacks and identify any antipredator strategies that they adopted, and (2) quantify the frequency of fosa attacks and the predation impact on the sifaka population. We report five direct observations of fosa predation attempts (one successful), the discovery of a dead sifaka with evidence of fosa predation, and the disappearance of three individuals. We describe the observed attacks and compare the sifaka activity budgets and movement patterns before and after the events. To escape the predator, sifakas fled short distances, hid, and remained vigilant. The impact of predation, combined with low reproductive rates and potentially high inbreeding of this isolated diademed sifaka population, could affect the survival of this species in Betampona. Given the compounding effects of habitat isolation and high hunting pressure, community-specific conservation strategies should incorporate predator-prey dynamics via longitudinal monitoring of predator and prey population densities and quantifying the predation pressure between them.

Evaluation of in vitro treatments against the causative agent of Diadema antillarum scuticociliatosis (DaSc).

In the 1980s, a mass die-off of the long-spined sea urchin Diadema antillarum occurred on Florida and Caribbean coral reefs. D. antillarum populations largely did not recover, and in 2022, remaining populations experienced another mass mortality event. A ciliate most similar to Philaster apodigitiformis was identified as the causative agent of the 2022 event, which was named D. antillarum scuticociliatosis (DaSc). Here, we investigated possible treatments for this pathogen. We tested the efficacy of 10 compounds at final concentrations of 100, 50, 25, 12.5, 6.25, and 3.13 µM, or a 10-fold serial dilution series, against ciliates cultured from an infected D. antillarum specimen. Of the tested compounds, 8 induced 100% ciliate mortality at some dose after 24 h. The most effective (defined as those requiring the lowest dose to induce 100% ciliate mortality) were quinacrine and tomatine (both effective at 12.5 µM), followed by furaltadone and plumbagin (25 µM), bithionol sulfoxide and 2'4' dihydroxychalcone (50 µM), and oxyclozanide and carnidazole (100 µM). Toltrazuril and a commercially available anticiliate product containing naphthoquinones were not effective at any dose tested. Shortened (15 min) time trials were performed using ciliate cultures reared in natural seawater to better reflect natural environmental conditions, and revealed that 2 of the compounds (quinacrine and tomatine) induced 100% ciliate mortality at 100 µM, with tomatine also effective at 50 µM. This study identified several treatments effective against the causative agent of DaSc in vitro, but their toxicity and utility in vivo remain unknown.

Transglobal spread of an ecologically relevant sea urchin parasite.

Mass mortality of the dominant coral reef herbivore Diadema antillarum in the Caribbean in the early 1980s contributed to a persistent phase shift from coral- to algal-dominated reefs. In 2022, a scuticociliate most closely related to Philaster apodigitiformis caused further mass mortality of D. antillarum across the Caribbean, leading to >95% mortality at affected sites. Mortality was also reported in the related species Diadema setosum in the Mediterranean in 2022, though the causative agent of the Mediterranean outbreak has not yet been determined. In April 2023, mass mortality of Diadema setosum occurred along the Sultanate of Oman's coastline. Urchins displayed signs compatible with scuticociliatosis including abnormal behavior, drooping and loss of spines, followed by tissue necrosis and death. Here we report the detection of an 18S rRNA gene sequence in abnormal urchins from Muscat, Oman, that is identical to the Philaster strain responsible for D. antillarum mass mortality in the Caribbean. We also show that scuticociliatosis signs can be elicited in Diadema setosum by experimental challenge with the cultivated Philaster strain associated with Caribbean scuticociliatosis. These results demonstrate the Philaster sp. associated with D. antillarum mass mortality has rapidly spread to geographically distant coral reefs, compelling global-scale awareness and monitoring for this devastating condition through field surveys, microscopy, and molecular microbiological approaches, and prompting investigation of long-range transmission mechanisms.

Seventeen-year study reveals fluctuations in key ecological indicators on two reef crests in Cuba.

Reef crests in the Caribbean have lost approximately 80% of the foundational habitat-forming coral Acropora palmata (Lamarck, 1816), with declines registered as early as the 1950s mainly from anthropogenic causes. We studied two reef crests in the northwestern region of Cuba over 17 years (2005 to 2021) to evaluate temporal changes in coral cover, dominated by A. palmata, and their potential drivers. The density of A. palmata generally showed a negative trend at both reefs, with the lowest density recorded in 2021 at 0.2 ± 0.05 col. m-2 at Playa Baracoa and 1.0 ± 0.1 col. m-2 at Rincon de Guanabo. The mean size of the colonies in the two reefs also decreased over time. In Playa Baracoa, the mean diameter of A. palmata colonies decreased from 2012 at 67 ± 5.9 cm to 2013 at 34 ± 2.2 cm, whereas in Rincon de Guanabo, a change in diameter was evident from 2015 at 44.3 ± 2.3 to 2021 at 21.6 ± 0.9 cm. Adult colonies (10 cm-50 cm diameter) predominated in most years on both reefs. The populations of A. palmata on both reefs were healthy, with an average of 70% colonies in good condition during the study period. However, A. palmata cover decreased by almost half by 2021, to 8.6% in Playa Baracoa and 16.8% in Rincon de Guanabo. By contrast, macroalgal cover increased two-fold to 87.1% in Playa Baracoa and four-fold to 77.2% in Rincon de Guanabo. The density of the sea urchin Diadema antillarum was higher in Playa Baracoa than in Rincon de Guanabo. The highest densities were 2.8 ± 0.2 ind. m-2 in Playa Baracoa in 2005 and 0.1 ± 0.03 ind. m-2 in Rincon de Guanabo in 2008. Although our results show an overall decline of A. palmata (density and percent cover) and an increase in macroalgae, these two reef crests are in better condition than most reefs in the Caribbean in terms of the density and health of A. palmata populations, and the density of D. antillarum at Playa Baracoa. Our results are important in establishing a management plan to ensure the condition of these reef crests does not degrade further.

Uneven demographic consequences of the 2022 disease outbreak for the sea urchin Diadema antillarum in Puerto Rico.

Pervasive epizootic events have had a significant impact on marine invertebrates throughout the Caribbean, leading to severe population declines and consequential ecological implications. One such event was the regional collapse of herbivory, partly caused by the Diadema antillarum mortality event in 1983-84, resulting in a trophic cascade and altering the structure of reef communities. Consequently, there was a notable decrease in coral recruitment and an increase in the coverage of macroalgae. Nearly four decades later, in early 2022, the Caribbean basin experienced another widespread mass mortality event, further reducing the populations of D. antillarum. To assess the effects of this recent mortality event on the current demographics of D. antillarum, we surveyed eight populations along the eastern, northeastern, northern, and northwestern coast of Puerto Rico from May to July 2022, estimating their population density, size distribution, and disease prevalence. Additionally, the study compared these population parameters with data from four sites previously surveyed in 2012 and 2017 to understand the impact of the recent mortality event. The survey conducted in 2022 showed varying population densities at the surveyed reefs. Some populations exhibited mean densities of nearly one individual per square meter, while others had extremely low or no living individuals per square meter. The four populations with the highest density showed no evidence of disease, whereas the four populations with the lowest D. antillarum densities exhibited moderate to high disease prevalence. However, when considering all sites, the estimated disease prevalence remained below 5%. Nevertheless, the comparison with data from 2012 and 2017 indicated that the recent mortality event had a negative impact on D. antillarum demographics at multiple sites, as the densities in 2022 were reduced by 60.19% compared to those from the previous years. However, it is still too early to determine the severity of this new mortality event compared to the 1983-84 mortality event. Therefore, it is imperative to continue monitoring these populations.

Comparison of feeding preferences of herbivorous fishes and the sea urchin Diadema antillarum in Little Cayman.

On Caribbean coral reefs, losses of two key groups of grazers, herbivorous fishes and Diadema antillarum, coincided with dramatic increases in macroalgae, which have contributed to decreases in the resilience of these coral reefs and continued low coral cover. In some locations, herbivorous reef fishes and D. antillarum populations have begun to recover, and reductions in macroalgal cover and abundance have followed. Harder to determine, and perhaps more important, are the combined grazing effects of herbivorous fishes and D. antillarum on the structure of macroalgal communities. Surprisingly few studies have examined the feeding preferences of D. antillarum for different macroalgal species, and there have been even fewer comparative studies between these different herbivore types. Accordingly, a series of in-situ and ex-situ feeding assays involving herbivorous fishes and D. antillarum were used to examine feeding preferences. Ten macrophytes representing palatable and chemically and/or structurally defended species were used in these assays, including nine macroalgae, and one seagrass. All species were eaten by at least one of the herbivores tested, although consumption varied greatly. All herbivores consumed significant portions of two red algae species while avoiding Halimeda tuna, which has both chemical and structural defenses. Herbivorous fishes mostly avoided chemically defended species while D. antillarum consumed less of the structurally defended algae. These results suggest complementarity and redundancy in feeding by these different types of herbivores indicating the most effective macroalgal control and subsequent restoration of degraded coral reefs may depend on the recovery of both herbivorous fishes and D. antillarum.

Activity budget and seasonal activity shifts in sympatric lemurs: Increased lean season effort in a cathemeral frugivore contrasts with energy conservation in a diurnal folivore.

One of the most fundamental aspects of a species' behavioral strategy is its activity budget; for primates this generally involves the allocation of available time among resting, feeding, traveling, and social behavior. Comparisons between species, populations, or individuals can reveal divergences in adaptive strategies and current stressors, and reflect responses to such diverse pressures as predation, thermoregulation, nutrition, and social needs. Further, variation across seasons is an important part of behavioral strategies to survive food scarcity; this can involve increasing or decreasing effort. We documented activity over the 24-h cycle for the cathemeral, frugivorous Eulemur fulvus and the diurnal, folivorous Propithecus diadema across 13-18 months at Tsinjoarivo, Madagascar. Their activity budgets were dominated by resting (E. fulvus: 74.1%; P. diadema: 85.2%), followed by feeding (15.8%, 12.4%), traveling (9.31%, 1.74%) and social activities (0.76%, 0.70%), respectively. The lower feeding and higher resting in P. diadema likely reflect slower gastrointestinal transit and higher reliance on microbial fermentation to extract energy from fibrous food. The two species showed opposite lean season strategies. E. fulvus increased activity, with more feeding but less travel time, consistent with a shift to less-profitable fruits, and some leaves and flowers, while increasing feeding effort to compensate ("energy maximizing"). P. diadema showed less variation across months, but the lean season still evoked reduced effort across the board (feeding, travel, and social behavior), consistent with a "time minimizing" strategy prioritizing energy conservation and microbe-assisted digestion. Understanding these divergent shifts is key to understanding natural behavior and the extent of behavioral flexibility under stressful conditions. Finally, the complex patterns of fruit availability (intra- and interannually) and the species' behavioral responses across months underscore the need to move beyond simplistic "lean/abundant season" and "fruit/leaf" dichotomies in understanding underlying energetic strategies, and species' vulnerability to habitat change.

Effects of Glyphosate on Female Reproductive Output in the Marine Polychaete Worm Ophryotrocha diadema.

Glyphosate is a broad-spectrum herbicide widely employed in agriculture. Exposure to this genotoxic and endocrine-disrupting compound has adverse effects on terrestrial and aquatic organisms and on humans as well. Here, we explored the effects of glyphosate on female reproductive output and somatic growth rate in the marine polychaete worm, Ophryotrocha diadema. Adult focal individuals were exposed to different concentrations of pure glyphosate (0.0, 0.125 0.250, 0.500, 1.000 µg/mL) administered once a week for 3 weeks. Toxic effects and mortalities were observed at the three higher concentrations, whereas only a decrease in growth rate was noted after exposure to 0.125 µg/mL, which did not affect female allocation. An area of focus in future studies should be the effects of contaminants, their metabolites, and ecologically relevant human-driven stressors in the context of global warming.

Mass mortality of the invasive alien echinoid Diadema setosum (Echinoidea: Diadematidae) in the Mediterranean Sea.

The sea urchin Diadema setosum is an ecological key species across its range, particularly on coral reefs. In 2006 D. setosum was first observed in the Mediterranean Sea, and since, it has proliferated to occupy the entire Levantine Basin. Here we report the mass mortality of the invasive D. setosum in the Mediterranean Sea. This is the first report of D. setosum mass mortality. The mortality spans over 1000 km along the Levantine coast of Greece and Turkey. The current mortality shows similar pathologies to previously reported Diadema mass mortality events, suggesting pathogenic infection as the cause of mortalities. Maritime transport, local currents, and fish predation of infected individuals may distribute pathogens at varying geographical scales. Due to the proximity of the Levantine Basin to the Red Sea, the risk of pathogen transport to the native Red Sea D. setosum population is imminent-with potentially catastrophic consequences.

Comparative analysis of temporal variation of heavy metal accumulation by two sea urchin species from a harbour region, including pre and post COVID 19 lock down period.

Sea urchins are marine invertebrates belonging to phylum Echinodermata, recognized as relevant biological tool for assessing environmental pollution. In the present study, we assessed the bioaccumulation potential of different heavy metals by two sea urchin species, Stomopneustes variolaris Lamarck, 1816 and Echinothrix diadema Linnaeus, 1758, collected from a harbour region, along the south west coast of India, during four different sampling periods for 2 years, from the same sea urchin bed. Heavy metals like Pb, Cr, As, Cd, Co, Se, Cu, Zn, Mn and Ni were analysed from water, sediment and different body parts of sea urchins, such as shell, spine, tooth, gut and gonad. The sampling periods also included the pre and post COVID 19 lockdown period during which the harbour activities were closed. The bio-water accumulation factor (BWAF), bio-sediment accumulation factor (BSAF) and the metal content/test weight index (MTWI) were calculated, in order to compare the bioaccumulation of metals by both the species. The results showed that S. variolaris had higher bioaccumulation potential than E. diadema, for metals like Pb, As, Cr, Co and Cd especially in the soft body parts like gut and gonad. The hard parts of S. variolaris like shell, spine, and tooth also accumulated more Pb, Cu, Ni and Mn than E. diadema. Following the lockdown period, there was a decline in the concentration of all heavy metals in water, whereas in sediment, Pb, Cr, and Cu levels were reduced. The gut and gonad tissues of both the urchins showed a decrease in the concentration of most of the heavy metals following the lockdown phase and no significant reduction was observed in the hard parts. This study reveals the use of S. variolaris as an excellent bioindicator of heavy metal contamination in the marine environment which can be employed for coastal monitoring programs.

Sea urchin mass mortalities 40 y apart further threaten Caribbean coral reefs.

In 1983 to 1984, a mass mortality event caused a Caribbean-wide, >95% population reduction of the echinoid grazer, Diadema antillarum. This led to blooms of algae contributing to the devastation of scleractinian coral populations. Since then, D. antillarum exhibited only limited and patchy population recovery in shallow water, and in 2022 was struck by a second mass mortality reported over many reef localities in the Caribbean. Half-a-century time-series analyses of populations of this sea urchin from St. John, US Virgin Islands, reveal that the 2022 event has reduced population densities by 98.00% compared to 2021, and by 99.96% compared to 1983. In 2021, coral cover throughout the Caribbean was approaching the lowest values recorded in modern times. However, prior to 2022, locations with small aggregations of D. antillarum produced grazing halos in which weedy corals were able to successfully recruit and become the dominant coral taxa. The 2022 mortality has eliminated these algal-free halos on St. John and perhaps many other regions, thereby increasing the risk that these reefs will further transition into coral-free communities.

Sea urchin (Diadema savignyi) extract as a novel protective agent against cisplatin induced neurotoxicity in rats.

Neurotoxicity is a severe side effect of platinum compounds used for cancer chemotherapy such as Cisplatin. This neurotoxicity leads to severe cognitive and nervous dysfunction, therefore, limiting the dose of Cisplatin and compromising the treatment protocol.The present study investigates the neuroprotective effect of Sea Urchins which is a marine animal known for its rich bioactive compounds. Male Sprague Dawley rats received Cisplatin (2 mg/kg body weight) for 4 weeks, two times per week, followed by Sea Urchin extracts (50 and 100 mg/kg body weight) twice weekly for 4 weeks.Results show that rats treated with Urchin's extracts showed a significant improvement in the thermal (heat and cold) sensitivity compared to untreated rats. Liver enzymes Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) and Urea levels were also significantly decreased back to normal following treatment with sea urchin extracts. Brain tissue oxidative stress marker Nitric oxide (NO) and lipid peroxidation marker Malondialdehyde (MDA) increased significantly in the cisplatin-treated rats while the reduced glutathione levels (GSH) and catalase activity (CAT) showed a significant decrease. Treatment with sea Urchin extracts reversed these changes.Histological and immunohistochemical examination of the cerebral cortex reveled degenerative changes such as karyopyknosis and shrunken necrotic ghost like neurons in the cisplatin treated groups. There was also strong positive Glial fibrillary acidic protein (GFAP) reactivity and a negative B-cell leukemia/lymphoma 2 protein (Bcl2) reaction in most apparent neurons, indicating strong apoptotic changes. Treatment with Urchin extracts reversed these changes. Quantification of cerebral cortex neurons also revealed the strong effect of the extracts. Cisplatin treated groups showed 3708 cells/ mm3 compared to 8091 cells/mm3 in the normal rats. Extract treatment increased the neuronal numbers to almost normal levels. Quantification of the Immuno-histochemical expression of GFAP showed an increase by 10-folds after cisplatin administration. A remarkable decline from the cisplatin group was seen in the extract treated groups.In Conclusion, Sea Urchins extracts possess a strong neuroprotective activity and could provide a novel therapeutic method to prevent Cisplatin-induced neurotoxicity.

A study on the extraction of chitin and chitosan from the invasive sea urchin Diadema setosum from Iskenderun Bay in the Northeastern Mediterranean.

This work presents, for the first time, the extraction and characterization of chitin and chitosan from the testa (T) and spines (S) of the invasive sea urchin (Diadema setosum) from the Iskenderun Bay in the Northeastern Mediterranean. Testa chitin (T-CT), spine chitin (S-CT), testa chitosan (T-CS), and spine chitosan (S-CS) were isolated following demineralization, deproteinization (chitin), and deacetylation (chitosan). The yield of chitin extraction from dry sea urchin testa (T-CT) and spines (S-CT) were 57.2 ± 1.43% and 67.1 ± 0.17%, respectively. The yield of chitosan produced from extracted testa (T-CS) and spines (S-CS) chitin were 87.3 ± 1.82% and 74.04 ± 1.27%, respectively. Degree of deacetylation (DD%) value were calculated using FT-IR (84.19% and 85.80%), resulting in a high DD. They were perfectly soluble in acidic solution. We also characterized the isolated chitin (T-CT and S-CT) and chitosan (T-CS and S-CS) by determining its physicochemical properties using X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscope analysis (SEM). Overall, the results indicated that the preparation of chitin and chitosan from the invasive sea urchin testa and spines could open the opportunity for the value-added seafood waste to be utilized in a wide range of practical applications such as medicine, pharmaceutical, and biotechnology.

Diadema setosum: isolation of bioactive secondary metabolites with cytotoxic activity toward human cervical cancer.

In our promising project toward discovery of secondary metabolites with potential anticancer activity against human cervical cancer, seven marine organisms were screened for their cytotoxic activity against HeLa cancer cell line using MTT colorimetric assay. The crude extract of the outer shell of Diadema setosum showed promising activity with 88.02% inhibition at a concentration 250 µg/ml. Chromatographic investigation of the Ethyl acetate fraction, which is the main contributor to the activity (IC50= 43.1 ± 5.94 µg/ml), led to isolation of five compounds. Structures of the isolates (1-5) were elucidated by 1 D and 2 D NMR spectroscopy and HR-ESI-MS analysis. 5α,8α-epidioxycholest-6-en-3ß ol (2) and 5α,8α-epidioxycholest-6,9(11)-en-3ß ol (3) showed the highest cytotoxic activity with IC50 values 12.1 ± 2.74 µg/ml and 21.8 ± 6.32 µg/ml, respectively. Epidioxy steroids with cholestane nucleus could be a prospective candidate for the development of drugs for treatment of human cervical cancer.

Biochemical composition of some Echinodermata (Holothuroidea, Echinoidea) from the Red Sea, Egypt / Composição bioquímica de alguns Echinodermata (Holothuroidea, Echinoidea) do Mar Vermelho, Egito

In the present study, the biochemical composition of some Echinodermata (Holothuroidea, Echinoidea) from the Red Sea, Egypt was investigated. The results showed that the highest percentage of saturated fatty acids (SFA) was in Holothuria nobilis and the lowest percentage was recorded in Holothuria scabra. The highest percentage of monounsaturated fatty acids (MUFA) was recorded in Pearsonothuria graeffei while the lowest percentage was recorded in Holothuria atra. The highest percentage of polyunsaturated fatty acids (PUFA) was recorded in Holothuria nobilis and the lowest percentage was recorded in Holothuria atra. The highest percentage of omega-3 fatty acids was recorded in Stichopus hermanni however, the lowest percentage was recorded in Diadema setosum. The highest percentage of omega-6 fatty acids was recorded in Bohadschia vitiensis where, the lowest percentage was recorded in Holothuria atra. In addition, nonessential amino acid (NEAA) glycine were the highest in all species and serine was the lowest while Essential amino acid (EAA) arginine was the highest and cysteine was the lowest. All of the NEAA recorded highest concentrations in S. hermanni except proline. The recorded essential amino acids were histidine, isoleucine, phenylalanine, and leucine. The latter was high in Pearsonothuria graeffei. Tyrosine, valine, threonine, and arginine were high in Stichopus hermanni. The present study proved that sea cucumbers has great nutritional value.

No presente estudo, investigou-se a composição bioquímica de algumas espécies Echinodermata (Holothuroidea, Echinoidea) do Mar Vermelho no Egito. Os resultados mostraram que a maior porcentagem de ácidos graxos saturados (SFA) foi na espécie Holothuria nobilis e a menor porcentagem foi registrada em Holothuria scabra. A maior porcentagem de ácidos graxos monoinsaturados (MUFA) foi registrada na espécie Pearsonothuria graeffei, enquanto a menor porcentagem foi registrada em Holothuria atra. O maior percentual de ácidos graxos poliinsaturados (PUFA) foi registrado em Holothuria nobilis e o menor percentual foi registrado em Holothuria atra. A maior porcentagem de ácidos graxos ômega-3 foi registrada na espécie Stichopus hermanni, entretanto, a menor porcentagem foi registrada em Diadema setosum. A maior porcentagem de ácidos graxos ômega-6 foi registrada em Bohadschia vitiensis e a menor porcentagem foi registrada em Holothuria atra. Além disso, o nível de aminoácido não-essencial (NEAA) glicina foi o mais alto em todas as espécies e o de serina foi o mais baixo, enquanto o nível de aminoácido essencial (EAA) arginina foi o mais alto e a cisteína foi o mais baixo. Todos os NEAA registraram concentrações mais altas em S. hermanni, exceto prolina. Os aminoácidos essenciais registrados foram histidina, isoleucina, fenilalanina e leucina. A leucina apresentou alto nível na espécie Pearsonothuria graeffei. Tirosina, valina, treonina e arginina apresentaram níveis elevados em Stichopus hermanni. Assim, o presente estudo comprovou que o pepino-do-mar possui grande valor nutricional.

Biochemical composition of some Echinodermata (Holothuroidea, Echinoidea) from the Red Sea, Egypt / Composição bioquímica de alguns Echinodermata (Holothuroidea, Echinoidea) do Mar Vermelho, Egito

In the present study, the biochemical composition of some Echinodermata (Holothuroidea, Echinoidea) from the Red Sea, Egypt was investigated. The results showed that the highest percentage of saturated fatty acids (SFA) was in Holothuria nobilis and the lowest percentage was recorded in Holothuria scabra. The highest percentage of monounsaturated fatty acids (MUFA) was recorded in Pearsonothuria graeffei while the lowest percentage was recorded in Holothuria atra. The highest percentage of polyunsaturated fatty acids (PUFA) was recorded in Holothuria nobilis and the lowest percentage was recorded in Holothuria atra. The highest percentage of omega-3 fatty acids was recorded in Stichopus hermanni however, the lowest percentage was recorded in Diadema setosum. The highest percentage of omega-6 fatty acids was recorded in Bohadschia vitiensis where, the lowest percentage was recorded in Holothuria atra. In addition, nonessential amino acid (NEAA) glycine were the highest in all species and serine was the lowest while Essential amino acid (EAA) arginine was the highest and cysteine was the lowest. All of the NEAA recorded highest concentrations in S. hermanni except proline. The recorded essential amino acids were histidine, isoleucine, phenylalanine, and leucine. The latter was high in Pearsonothuria graeffei. Tyrosine, valine, threonine, and arginine were high in Stichopus hermanni. The present study proved that sea cucumbers has great nutritional value.

No presente estudo, investigou-se a composição bioquímica de algumas espécies Echinodermata (Holothuroidea, Echinoidea) do Mar Vermelho no Egito. Os resultados mostraram que a maior porcentagem de ácidos graxos saturados (SFA) foi na espécie Holothuria nobilis e a menor porcentagem foi registrada em Holothuria scabra. A maior porcentagem de ácidos graxos monoinsaturados (MUFA) foi registrada na espécie Pearsonothuria graeffei, enquanto a menor porcentagem foi registrada em Holothuria atra. O maior percentual de ácidos graxos poli insaturados (PUFA) foi registrado em Holothuria nobilis e o menor percentual foi registrado em Holothuria atra. A maior porcentagem de ácidos graxos ômega-3 foi registrada na espécie Stichopus hermanni, entretanto, a menor porcentagem foi registrada em Diadema setosum. A maior porcentagem de ácidos graxos ômega-6 foi registrada em Bohadschia vitiensis e a menor porcentagem foi registrada em Holothuria atra. Além disso, o nível de aminoácido não-essencial (NEAA) glicina foi o mais alto em todas as espécies e o de serina foi o mais baixo, enquanto o nível de aminoácido essencial (EAA) arginina foi o mais alto e a cisteína foi o mais baixo. Todos os NEAA registraram concentrações mais altas em S. hermanni, exceto prolina. Os aminoácidos essenciais registrados foram histidina, isoleucina, fenilalanina e leucina. A leucina apresentou alto nível na espécie Pearsonothuria graeffei. Tirosina, valina, treonina e arginina apresentaram níveis elevados em Stichopus hermanni. Assim, o presente estudo comprovou que o pepino-do-mar possui grande valor nutricional.

Biochemical composition of some Echinodermata (Holothuroidea, Echinoidea) from the Red Sea, Egypt

Abstract In the present study, the biochemical composition of some Echinodermata (Holothuroidea, Echinoidea) from the Red Sea, Egypt was investigated. The results showed that the highest percentage of saturated fatty acids (SFA) was in Holothuria nobilis and the lowest percentage was recorded in Holothuria scabra. The highest percentage of monounsaturated fatty acids (MUFA) was recorded in Pearsonothuria graeffei while the lowest percentage was recorded in Holothuria atra. The highest percentage of polyunsaturated fatty acids (PUFA) was recorded in Holothuria nobilis and the lowest percentage was recorded in Holothuria atra. The highest percentage of omega-3 fatty acids was recorded in Stichopus hermanni however, the lowest percentage was recorded in Diadema setosum. The highest percentage of omega-6 fatty acids was recorded in Bohadschia vitiensis where, the lowest percentage was recorded in Holothuria atra. In addition, nonessential amino acid (NEAA) glycine were the highest in all species and serine was the lowest while Essential amino acid (EAA) arginine was the highest and cysteine was the lowest. All of the NEAA recorded highest concentrations in S. hermanni except proline. The recorded essential amino acids were histidine, isoleucine, phenylalanine, and leucine. The latter was high in Pearsonothuria graeffei. Tyrosine, valine, threonine, and arginine were high in Stichopus hermanni. The present study proved that sea cucumbers has great nutritional value.

Resumo No presente estudo, investigou-se a composição bioquímica de algumas espécies Echinodermata (Holothuroidea, Echinoidea) do Mar Vermelho no Egito. Os resultados mostraram que a maior porcentagem de ácidos graxos saturados (SFA) foi na espécie Holothuria nobilis e a menor porcentagem foi registrada em Holothuria scabra. A maior porcentagem de ácidos graxos monoinsaturados (MUFA) foi registrada na espécie Pearsonothuria graeffei, enquanto a menor porcentagem foi registrada em Holothuria atra. O maior percentual de ácidos graxos poli-insaturados (PUFA) foi registrado em Holothuria nobilis e o menor percentual foi registrado em Holothuria atra. A maior porcentagem de ácidos graxos ômega-3 foi registrada na espécie Stichopus hermanni, entretanto, a menor porcentagem foi registrada em Diadema setosum. A maior porcentagem de ácidos graxos ômega-6 foi registrada em Bohadschia vitiensis e a menor porcentagem foi registrada em Holothuria atra. Além disso, o nível de aminoácido não-essencial (NEAA) glicina foi o mais alto em todas as espécies e o de serina foi o mais baixo, enquanto o nível de aminoácido essencial (EAA) arginina foi o mais alto e a cisteína foi o mais baixo. Todos os NEAA registraram concentrações mais altas em S. hermanni, exceto prolina. Os aminoácidos essenciais registrados foram histidina, isoleucina, fenilalanina e leucina. A leucina apresentou alto nível na espécie Pearsonothuria graeffei. Tirosina, valina, treonina e arginina apresentaram níveis elevados em Stichopus hermanni. Assim, o presente estudo comprovou que o pepino-do-mar possui grande valor nutricional.

Abundance and population characteristics of the invasive sea urchin Diadema setosum (Leske, 1778) in the south Aegean Sea (eastern Mediterranean).

BACKGROUND: The Indo-Pacific sea urchin Diadema setosum has invaded the Mediterranean Sea and has spread along many locations in the southeastern part of the basin, where established populations exist on the shallow subtidal rocky shore. Diadema setosum is a ubiquitous species, of particular ecological importance due to the high levels of grazing pressure it imposes on benthic communities. Its biology, however, is not adequately studied, especially along its introduced range of distribution. The present study examines the population status of D. setosum outside its native range, in the Dodecanese island complex, south Aegean Sea. Thirty-four stations located across 16 islands were surveyed by scientific SCUBA-diving (up to a depth of 10 m) in December 2019 and June-July 2020. Samplings included: (i) visual census along transects to estimate relative abundance and population density, and (ii) random collection of specimens from densely populated stations to assess biometry and reproductive condition (histological examination of gonads) of D. setosum. RESULTS: Diadema setosum was found in 21 out of the 34 surveyed stations. The species had sparse populations of well-hidden individuals in rocky crevices, but with dense localized patches in Agathonisi, Leros, Kalymnos, Pserimos, Symi, Alimia and Chalki islands. In those seven islands, mean population density was 2.5 ± 1.48 individuals m-2. Diadema setosum had denser populations in shallower depths but larger dimensions in deeper; these results suggest segregated density and size patterns along a depth gradient. The size structure, according to the size frequency distribution of the test diameter, was unimodal with a fitted mode at 4.0-4.5 and 6.5-7.0 cm in shallow and deep populations, respectively. The examined morphometric relationships followed negative allometry, as previously suggested for the species within its native range of distribution, and test diameter appeared to be a good predictor of biomass. Diadema setosum specimens had immature gonads in winter and mature in summer, suggesting a synchronous reproductive pattern. These results conform to previous data from temperate populations of the species. CONCLUSIONS: Differences in local environmental conditions, e.g. hydrodynamics and habitat type, together with biotic interactions, e.g. recruitment and competition, probably shape D. setosum population in the south Aegean distributional range. The establishment of D. setosum has severe implications on benthic communities and local sea urchin populations demanding management measures to prevent the forecasted further expansion of this invasive species.

Toxicological risks on the human health of populations living around the Mediterranean Sea linked to the invasion of non-indigenous marine species from the Red Sea: A review.

The Mediterranean region is, by far, a prime travel destination, having hosted more than 330 million tourists in 2016, mostly for seaside holidays. A greatly increased influx of thermophilic Red Sea species, introduced through the Suez Canal in a process referred to as Lessepsian invasion (in honor of Ferdinand de Lesseps who instigated the building of the Suez Canal), have raised awareness among scientists, medical personnel, and the public, of health risks caused by some venomous and poisonous marine species. The main species of concern are the poisonous Lagocephalus sceleratus, and the venomous Plotosus lineatus, Siganus luridus, Siganus rivulatus, Pterois miles, Synancea verrucosa, Rhopilema nomadica, Macrorhynchia philippina and Diadema setosum. Recognizing that the main factors that drive the introduction and dispersal of Red Sea biota in the Mediterranean, i.e., Suez Canal enlargements and warming seawater, are set to increase, and international tourist arrivals are forecasted to increase as well, to 500 million in 2030, an increase in intoxications and envenomations by alien marine species is to be expected and prepared for.

Uncommon southwest swells trigger sea urchin disease outbreaks in Eastern Atlantic archipelagos.

Recurrent sea urchin mass mortality has recently affected eastern Atlantic populations of the barren-forming sea urchin Diadema africanum. This new episode of die-off affords the opportunity to determine common meteorological and oceanographic conditions that may promote disease outbreaks. The population dynamics of this sea urchin species are well known-urchin barrens have persisted for many decades along most of the coastlines off the archipelagos of Madeira, Selvages, and the Canary Islands, where they limit macroalgae biomass growth. However, this new and explosive mortality event decimated the sea urchin population by 93% on Tenerife and La Palma Islands. Two severe episodes of southwestern rough sea that led to winter storms, in February 2010 (Xynthia) and February 2018 (Emma), preceded both mass mortality events. The autumn and winter months of those years were anomalous and characterized by swells with an average wave height above 2 m that hit the south and southwest sides of the islands. The amoeba Paramoeba brachiphila was the only pathogen isolated this time from the moribund and dead sea urchins, suggesting that the amoeba was the primary cause of the mortality. This new sea urchin die-off event supports the "killer-storm" hypothesis that has been already described for western Atlantic coasts. These anomalous southwest storms during winters generate pronounced underwater sediment movement and large-scale vertical mixing, detected in local tide gauge, which may promote paramoebiasis. This study presents valuable insights about climate-mediated changes in disease frequency and its impacts on the future of coastal marine ecosystems in the Atlantic.