Starfish Research Articles

Effects of embryo energy, egg size, and larval food supply on the development of asteroid echinoderms.

Organisms have limited resources available to invest in reproduction, causing a trade‐off between the number and size of offspring. One consequence of this trade‐off is the evolution of disparate egg sizes and, by extension, developmental modes. In particular, echinoid echinoderms (sea urchins and sand dollars) have been widely used to experimentally manipulate how changes in egg size affect development. Here, we test the generality of the echinoid results by (a) using laser ablations of blastomeres to experimentally reduce embryo energy in the asteroid echinoderms (sea stars), Pisaster ochraceus and Asterias forbesi and (b) comparing naturally produced, variably sized eggs (1.7‐fold volume difference between large and small eggs) in A. forbesi. In P. ochraceus and A. forbesi, there were no significant differences between juveniles from both experimentally reduced embryos and naturally produced eggs of variable size. However, in both embryo reduction and egg size variation experiments, simultaneous reductions in larval food had a significant and large effect on larval and juvenile development. These results indicate that (a) food levels are more important than embryo energy or egg size in determining larval and juvenile quality in sea stars and (b) the relative importance of embryo energy or egg size to fundamental life history parameters (time to and size at metamorphosis) does not appear to be consistent within echinoderms.

Purification and biochemical characterization of fibrino(geno)lytic enzymes from tissues of Antarctic hydrobionts

Considering the continuing increase of morbidity and mortality rates associated with cardiovascular diseases, the search for novel compounds able to affect the hemostasis system is among the current trends of modern science and pharmacology. Fibrino(geno)lytic enzymes because of their role in dissolving blood clots as well as prevention of their formation attract special attention. The main goal of the current research was to develop the methodological approaches to obtain fibrino(geno)lytic enzymes from Antarctic hydrobionts and study their effects on the functioning of the hemostasis system. A complex approach which included affinity chromatography and size-exclusion chromatography was applied to isolate the fibrino(geno)lytic enzymes from the tissue of Antarctic nemertea (Parborlasia corrugatus), Antarctic sea urchin (Sterechinus neumayeri), and Antarctic sea star (Odontaster validus). The presence of proteolytic activity was monitored by zymographic technique. Fibrin(ogen)olytic activity was assessed by incubation of the samples with fibrinogen followed by 10% SDS-PAGE analysis. To test the substrate specificity of the enzymes, the chromogenic substrates such as H-D-Phe-Pip-Arg-pNA, pyroGlu-Pro-Arg-pNA, H-D-Val-Leu-Lys-pNA and Bz-IIe-Glu(γ-OR)-Gly-Arg-pNA were used. The influence of fib rino(geno)lytic enzymes on platelet aggregation was assessed in platelet-rich plasma. To analyze the effect of the fibrino(geno)lytic enzymes on coagulation the blood coagulation time was assessed. The obtained results clearly indicated the presence of enzymes with activity toward fibrinogen in the tissues of tested hydrobionts. Based on the results of SDS-PAGE and zymography the molecular weight of the fibrino(geno)lytic enzymes was in the range of 26–34 kDa. The fibrinogen cleavage pattern analyzed by SDS-PAGE revealed the susceptibility of fibrinogen chains to degradation by enzymes from tissues of Antarctic hydrobionts. The fibrino(geno)lytic enzymes from all tested hydrobionts cleaved preferentially the Aα-chain and more slowly the Bβ-chain of fibrinogen. The fibrino(geno)lytic enzymes mediated the significant prolongation of blood clotting time in chronometric tests and inhibition of ADP-induced platelet aggregation. The enzymes exhibit activity against chromogenic substrates, which was more expressed in case of pyroGlu-Pro-Arg-pNA — a specific synthetic substrate for activated protein C and factor XIa. The enzymes isolated from the tissues of Antarctic marine hydrobionts possess a fibrin(ogen)olytic activity and can be of medical interest as therapeutic agents in the treatment and prevention of thrombotic disorders.

An Investigation into the Genetic History of Japanese Populations of Three Starfish, Acanthaster planci, Linckia laevigata, and Asterias amurensis, Based on Complete Mitochondrial DNA Sequences.

Crown-of-thorns starfish, Acanthaster planci (COTS), are common in coral reefs of Indo-Pacific Ocean. Since they are highly fecund predators of corals, periodic outbreaks of COTS cause substantial loss of healthy coral reefs. Using complete mitochondrial DNA sequences, we here examined how COTS outbreaks in the Ryukyu Archipelago, Japan are reflected by the profile of their population genetics. Population genetics of the blue starfish, Linckia laevigata, which lives in the Ryukyu Archipelago, but not break out and the northern Pacific sea star, Asterias amurensis, which lives in colder seawater around the main Islands of Japan, were also examined as controls. Our results showed that As. amurensis has at least two local populations that diverged approximately 4.7 million years ago (MYA), and no genetic exchanges have occurred between the populations since then. Linckia laevigata shows two major populations in the Ryukyu Archipelago that likely diverged ∼6.8 MYA. The two populations, each comprised of individuals collected from coast of the Okinawa Island and those from the Ishigaki Island, suggest the presence of two cryptic species in the Ryukyu Archipelago. On the other hand, population genetics of COTS showed a profile quite different from those of Asterias and Linckia. At least five lineages of COTS have arisen since their divergence ∼0.7 MYA, and each of the lineages is present at the Okinawa Island, Miyako Island, and Ishigaki Island. These results suggest that COTS have experienced repeated genetic bottlenecks that may be associated with or caused by repeated outbreaks.

Correction to 'Extraordinarily rapid life-history divergence between Cryptasterina sea star species'.

Correction to 'Extraordinarily rapid life-history divergence between Cryptasterina sea star species'.

Size structure and preyed corals of Acanthaster planci (crown-of-thorns sea star) in Lungui Island, Dimataling, Southern Philippines

Size structure and preyed corals of Acanthaster planci (crown-of-thorns sea star) in Lungui Island, Dimataling, Southern Philippines

Sea star-inspired recombinant adhesive proteins self-assemble and adsorb on surfaces in aqueous environments to form cytocompatible coatings

Sea stars adhere to various underwater substrata using an efficient protein-based adhesive secretion. The protein Sfp1 is a major component of this secretion. In the natural glue, it is cleaved into four subunits (Sfp1 Alpha, Beta, Delta and Gamma) displaying specific domains which mediate protein-protein or protein-carbohydrate interactions. In this study, we used the bacterium E. coli to produce recombinantly two fragments of Sfp1 comprising most of its functional domains: the C-terminal part of the Beta subunit (rSfp1 Beta C-term) and the Delta subunit (rSfp1 Delta). Using native polyacrylamide gel electrophoresis and size exclusion chromatography, we show that the proteins self-assemble and form oligomers and aggregates in the presence of NaCl. Moreover, they adsorb onto glass and polystyrene upon addition of Na+ and/or Ca2+ ions, forming homogeneous coatings or irregular meshworks, depending on the cation species and concentration. We show that coatings made of each of the two proteins have no cytotoxic effects on HeLa cells and even increase their proliferation. We propose that the Sfp1 recombinant protein coatings are valuable new materials with potential for cell culture or biomedical applications. Statement of SignificanceBiological adhesives offer impressive performance in their natural context and, therewith, the potential to inspire the development of advanced biomaterials for an increasing variety of applications in medicine or in material sciences. To date, most marine adhesive proteins that have been produced recombinantly in order to develop bio-inspired adhesives are small proteins from mussels and barnacles. Here, we produced two multi-modular proteins based on the sequence of Sfp1, a major protein from sea star adhesive secretion. These two proteins comprise most of Sfp1 functional domains which mediate protein-protein and protein-carbohydrate interactions. We characterized the two recombinant proteins with an emphasis on functional characteristics such as self-assembly, adsorption and cytocompatibility. We discuss their potential as biomaterials.

Molecular insights into the powerful mucus-based adhesion of limpets (Patella vulgata L.).

Limpets (Patella vulgata L.) are renowned for their powerful attachments to rocks on wave-swept seashores. Unlike adult barnacles and mussels, limpets do not adhere permanently; instead, they repeatedly transition between long-term adhesion and locomotive adhesion depending on the tide. Recent studies on the adhesive secretions (bio-adhesives) of marine invertebrates have expanded our knowledge on the composition and function of temporary and permanent bio-adhesives. In comparison, our understanding of the limpets' transitory adhesion remains limited. In this study, we demonstrate that suction is not the primary attachment mechanism in P. vulgata; rather, they secrete specialized pedal mucus for glue-like adhesion. Through combined transcriptomics and proteomics, we identified 171 protein sequences from the pedal mucus. Several of these proteins contain conserved domains found in temporary bio-adhesives from sea stars, sea urchins, marine flatworms and sea anemones. Many of these proteins share homology with fibrous gel-forming glycoproteins, including fibrillin, hemolectin and SCO-spondin. Moreover, proteins with potential protein- and glycan-degrading domains could have an immune defence role or assist degrading adhesive mucus to facilitate the transition from stationary to locomotive states. We also discovered glycosylation patterns unique to the pedal mucus, indicating that specific sugars may be involved in transitory adhesion. Our findings elucidate the mechanisms underlying P. vulgata adhesion and provide opportunities for future studies on bio-adhesives that form strong attachments and resist degradation until necessary for locomotion.

Adsorption of Heavy Metals in an Aqueous Solution Using Starfish (Asterina Pectinifera) Biochar

Objectives:Heavy metals caused by industrialization have affected human society for several decades. Because of their toxicity for humans, lots of heavy metal treatments have been developed. However, many of those treatments have economic considerations and environmental disadvantages. This work explored an experimental assessment of adsorption of heavy metals using starfish (SF) biochar through quantitative and qualitative characterization and batch-tests.Methods:Biochar (NACSF) was produced at 300℃ for 2 h in anaerobic conditions. The NACSF was characterized with XRD, XRF, FT-IR, SEM-EDX and elemental analyses. Moreover, batch-tests for each heavy metal using NACSF were conducted with ICP-OES analyses in order to evaluate the adsorption characteristics.Results and Discussion:Based on the characterization results, the NACSF consisted of carbon and CaCO<sub>3</sub> mainly. The adsorption rates of Pb, Cu, Zn and Cd decreased in the following order: Pb≫Cu>Zn≥Cd. Moreover, the Langmuir equation fit all adsorption data better than the Freundlich equation. Also, due to the alkalinity of NACSF, the measured pH values of all experimental groups were approximately 7~8.Conclusions:The NACSF treatment was the most effective for Pb removal and it was determined that precipitation and surface adsorption were the most likely mechanisms for Pb removal. Thus, NACSF derived from starfish could be an cost-effective and eco-friendly treatment for heavy metal contaminated wastewater.

The Sea Star Invertebrate Primitive Antibody (IPA):Rosetting And PFC (Plaque-Forming Cell). Anti-SRBC Antibodies

Next to the sea star T and B lymphocytes, we find the IPA (Invertebrate Primitive Antibody). Rosetting test and PFC test after Injection of SRBC (Sheep red blood cells)were performed in the sea starAsterias rubens (Echinodermata). Positive results were obtained and summarized in this work. They indicated the presence of anti-SRBC antibodies in the sea star, according to the method of Cunningham.

Temporal pattern of offspring release and degree of parental investment in two viviparous asterinid sea stars with an overview of matrotrophy and offspring size variation in echinoderms that care for their offspring

ABSTRACT The temporal pattern of juvenile release by two species of viviparous asterinid sea stars that incubate their young in the gonads was documented. Parvulastra parvivipara released juveniles (400–3000 µm diameter) in 1–5 cohorts. Parents produced large juveniles (>1000-µm) irrespective of adult size. Released juveniles were larger than the retained juveniles. Most Cryptasterina hystera offspring were released in one large clutch of similarly sized juveniles (732-µm mean diameter). After this initial release, the presence of large juveniles (944-µm mean diameter) in the gonads of C. hystera indicates that they are supported by matrotrophy, potentially through sibling cannibalism. The degree of parental investment additional to the egg in both species was estimated by using a matrotrophy index (MI, the ratio of juvenile and egg dry mass). As the eggs of P. parvivipara and C. hystera could not be isolated, the eggs of their congeners (P. exigua and C. pentagona, respectively) were used as a proxy to estimate the MI, the first application of this index to a marine invertebrate. The MI ranged from 597 to 55082 in P. parvivipara and 1.7–6.2 in C. hystera for juveniles across the different size classes. Matrotrophy and size variation of offspring may be characteristics of echinoderms that incubate their young.

Antimicrobial activity of the sea star (Astropecten spinulosus) collected from the Egyptian Mediterranean Sea, Alexandria

A species of sea star was collected from the Mediterranean Sea, Alexandria, Egypt. It was identified based on general morphological and anatomical features as Astropectenspinulosus. The antibacterial and antifungal activities were investigated via the standard techniques. Data obtained revealed that the inhibition zones as a factor for antibacterial activity of A. spinulosus ranged between 0 and 18 mm. The highest antibacterial activity was detected against P. aeruginosa (18 mm) for ethanol extract, followed by B. subtlis (14 mm) for methanol extract, then by P. aeruginosa (13 mm) for both ethyl acetate and methanol extract. Different solvent extracts recorded inhibition zones as antifungal activity ranged between 8 to 10 mm. the most suppressed fungus was P. crustosum by acetone and ethanol extracts as80 and 90%, respectively. Weakly, A. terreus was suppressed by ethanol and methanol extracts of A. spinulosus as 10 and 20%, respectively. The suppression was not taken place against other fungi by any solvent extract. Regarding to investigating the efficacy of some commercial antibiotics (mm), data confirmed that the Gram-negative bacteria were more resistant than Gram-positive bacteria. On the other side, the result of GC-MS/MS of crude extract observed the presence of several bioactive constituents, most of which had antimicrobial activities.

STRUKTUR KOMUNITAS, PERANAN DAN ADAPTASI MAKROALGA DI INTERTIDAL BERBATU

Rocky shore intertidal occurs at the interface of the land and sea, which regularly exposed with tidal waves. In general, rocky shore intertidal is influenced by extreme physical factors, so organisms need to adapt well. Macroalgae on rocky shore intertidal are mostly macroalgae that have epilithic life foam, for example, Sargassum, Turbinaria, Hypnea, Gracilaria, Amphiroa, Chaetomorpha, Ulva, Acanthophora, and Gelidium. The role of macroalgae on rocky shore intertidal are as a primary producer/primary productivity, food for other organisms (fish, mollusc, sea urchin, crab), nursery ground for other organisms (fish, sea urchin, sea cucumber, and crab), and provide shelter for benthic fauna (crabs, sea urchin, molluscs, polychaeta and sea star). The adaptation of macroalgae on rocky shore intertidal was through morphological changes. Gracilaria salicornia on rocky shore intertidal has slimmer thallus than G. salicornia on non-rocky shore intertidal.

Warming and temperature variability determine the performance of two invertebrate predators

In a warming ocean, temperature variability imposes intensified peak stress, but offers periods of stress release. While field observations on organismic responses to heatwaves are emerging, experimental evidence is rare and almost lacking for shorter-scale environmental variability. For two major invertebrate predators, we simulated sinusoidal temperature variability (±3 °C) around todays’ warm summer temperatures and around a future warming scenario (+4 °C) over two months, based on high-resolution 15-year temperature data that allowed implementation of realistic seasonal temperature shifts peaking midpoint. Warming decreased sea stars’ (Asterias rubens) energy uptake (Mytilus edulis consumption) and overall growth. Variability around the warming scenario imposed additional stress onto Asterias leading to an earlier collapse in feeding under sinusoidal fluctuations. High-peak temperatures prevented feeding, which was not compensated during phases of stress release (low-temperature peaks). In contrast, increased temperatures increased feeding on Mytilus but not growth rates of the recent invader Hemigrapsus takanoi, irrespective of the scale at which temperature variability was imposed. This study highlights species-specific impacts of warming and identifies temperature variability at the scale of days to weeks/months as important driver of thermal responses. When species’ thermal limits are exceeded, temperature variability represents an additional source of stress as seen from future warming scenarios.

In vitro protective effects of marine-derived Aspergillus puulaauensis TM124-S4 extract on H2O2-stressed primary human fibroblasts

Nowadays, there is a huge interest in natural products obtained from marine organisms that can promote human health.The aim of the present study is to evaluate for the first time, the in vitro effects of marine Aspergillus puulaauensis TM124-S4 extract against oxidative stress in human fibroblasts, and its potential as a cosmetic ingredient. The strain was isolated from the Mediterranean Sea star, Echinaster sepositus, and identified according to ITS molecular sequence homology as a member of Aspergillus section versicolores.To gain insight on the bioactivity underpinning the effects of TM124-S4 extract on oxidative stress, we examined a panel of a hundred genes as well as cell viability. Initially, Aspergillus puulaauensis TM124-S4 promoted cell viability.The change in gene transcripts revealed that Aspergillus puulaauensis TM124-S4 extracts exhibited skin protection properties by mediating cell proliferation (EPS8, GDF15, CASP7, VEGFA), antioxidant response (CAT, SOD1, TXN, GPX1), skin hydration (CD44, CRABP2, SERPINE) and DNA repair (PCNA, P21). The extract also modulated the expression of genes involved in skin pigmentation and aging (TYR, FOXO3).These findings indicate that Aspergillus puulaauensis TM124-S4 extract possesses significant in-vitro skin protection activity against induced oxidative stress.Furthermore, new insights are provided into the beneficial role of fungal bioactive compounds in skin related research.

Notes on some crinoid associated decapod crustaceans (Crustacea: Decapoda) of Lakshadweep Archipelago, Central Indian Ocean

Decapod crustaceans symbiotic with echinoderms (sea stars, brittle stars, feather stars, basket stars, sea cucumbers, and sea urchins) possess remarkable diversification in the Indo-Pacific. In the present study, seven species of decapod crustaceans symbiotic with crinoids are recorded based on collections from selected Islands (Agatti, Amini, Bangaram, Kavaratti, Kalpeni, and Minicoy) of Lakshadweep Archipelago. Of these decapods, five caridean shrimps (Alpheidae: Synalpheus carinatus (de Man, 1888), S. comatularum (Haswell, 1882), S. stimpsonii (de Man, 1888); Palaemonidae: Palaemonella pottsi (Borradaile, 1915), Pontoniopsis comanthi (Borradaile, 1915), one brachyuran crab [Pilumnidae: Permanotus purpureus (Gordon, 1934)] and one squat lobster [Galatheidae: Allogalathea elegans (Adams White, 1848)] were identified. The caridean shrimps have associated with the crinoids Comaster multifidus (Müller, 1841), Phanogenia gracilis (Hartlaub, 1893), P. distincta (Carpenter, 1888), P. multibrachiata (Carpenter, 1888) and Stephanometra indica (Smith, 1876). The brachyuran crab was observed in association with the crinoid Phanogenia gracilis whereas the squat lobsters were associated with Stephanometra tenuipinna (Hartlaub, 1890) and S. indica. Except S. stimpsonii and P. purpureus, all other species were recorded for the first time from India. Here, we provide details on morphology, distribution, habitat, and hosts for all species. We recommend further exploration of the sub-shallow coral reef areas of Lakshadweep as there will be many species that certainly remain to be discovered.

The Invertebrate Antibody

Introduction Many researchers don’t believe in our works: they speak we are wrong when we evoke the Invertebrate Antibody...BUT: Discussion We have discovered, in the past, the sea star lymphocytes ( B and T sea star lymphocytes : cf Fig 1,2) : these cells of 4-5µ in diameter are smaller than Vertebrate lymphocytes And ...We discovered recently the IPA (Invertebrate Primitive Antibody) with the sea star IGKAPPA gene with IG sites (Meta Gene 2013). Therefore genomic data assert the evidence of primitive antibody in Echinodermata. Furthermore, we find MHC genes class I and class II in 2019 and Fab gene, Fc receptor gene in these Invertebrates

Models with environmental drivers offer a plausible mechanism for the rapid spread of infectious disease outbreaks in marine organisms

The first signs of sea star wasting disease (SSWD) epidemic occurred in just few months in 2013 along the entire North American Pacific coast. Disease dynamics did not manifest as the typical travelling wave of reaction-diffusion epidemiological model, suggesting that other environmental factors might have played some role. To help explore how external factors might trigger disease, we built a coupled oceanographic-epidemiological model and contrasted three hypotheses on the influence of temperature on disease transmission and pathogenicity. Models that linked mortality to sea surface temperature gave patterns more consistent with observed data on sea star wasting disease, which suggests that environmental stress could explain why some marine diseases seem to spread so fast and have region-wide impacts on host populations.

Review: Some Animals Are More Equal than Others: Keystone Species and Trophic Cascades and Exploring Earth's Keystone Species

At the beginning of every school year, many educators are asked to prepare lesson plans for each course they teach, to be used in the case of an emergency absence. Teachers struggle to find resources that are not only engaging, but also present relevant information in a way students can understand without a teacher being there to translate for them. The Howard Hughes Medical Institute (HHMI) BioInteractive website hosts a vast library of biology-related media resources, virtual labs, and simulations that can be used under these circumstances. Two lessons of note include the film entitled Some Animals Are More Equal than Others: Keystone Species and Trophic Cascades and a related Google Earth Voyager module called Exploring Earth's Keystone Species.The short film opens by explaining pioneering research by Robert Paine and James Estes into interactions between sea star, sea urchin, and sea otter populations and their effects on the local Washington State kelp forests. The key concepts covered encompass topics that link across the entire biology or environmental science content, including population dynamics, food webs, trophic structure, biodiversity, ecosystem stability, species interactions, and experimental design. Covering all of these topics makes the film appropriate to show at any point in the course curriculum. Moreover, the video is short, only 20 minutes, which leaves plenty of time for students to discuss and analyze the information and apply their understanding to activities. Students could discuss ideas such as causal loop modeling of a kelp forest, completing a claim-evidence-reasoning prompt, or making predictions related to a different ecosystem of study. The HHMI website has a pretty highly cognitively demanding set of prompts that could fill several class periods with deep discussions related to these areas.Moreover, HHMI has partnered with Google Earth to provide a Voyager module entitled Exploring Earth's Keystone Species to accompany the video that students will find especially interesting. In this module, students explore other keystone species from around the world, such as the gray wolf, Eurasian beaver, and African elephant. In each location, students are provided a slideshow with captivating imagery, a short description of the organism, and the ability to explore the animal's habitat in greater detail. Be sure to give students a time limit or they could get sucked in for hours! Adding this Google Earth activity to the video is a high-leverage teacher move, not only because it will prompt more detailed discussions and deeper connections to the topic, but also because it presents the content in a more culturally relevant manner. It provides a greater diversity of examples with which students can develop personal connections.Finally, when combined, these two resources provide a challenging, differentiated, and diverse set of learning tasks that engage students in authentic learning in a personally meaningful way. It challenges students to think beyond their classroom about keystone species and human impacts on these species from a more global perspective. This will hopefully lead the students to the place every biology teacher wants their students to go – having them be better stewards of their dynamic and fragile planet.

Disturbances drive changes in coral community assemblages and coral calcification capacity

AbstractAnthropogenic environmental change has increased coral reef disturbance regimes in recent decades, altering the structure and function of many coral reefs globally. In this study, we used coral community survey data collected from 1996 to 2015 to evaluate reef‐scale coral calcification capacity (CCC) dynamics with respect to recorded pulse disturbances for 121 reef sites in the Main Hawaiian Islands and Mo'orea (French Polynesia) in the Pacific and the Florida Keys Reef Tract and St. John (U.S. Virgin Islands) in the western Atlantic. CCC remained relatively high in the Main Hawaiian Islands in the absence of recorded widespread disturbances; declined and subsequently recovered in Mo'orea following a crown‐of‐thorns sea star outbreak, coral bleaching, and major cyclone; decreased and remained low following coral bleaching in the Florida Keys Reef Tract; and decreased following coral bleaching and disease in St. John. Individual coral taxa have variable calcification rates and susceptibility to disturbances because of their differing life‐history strategies. As a result, temporal changes in CCC in this study were driven by shifts in both overall coral cover and coral community composition. Analysis of our results considering coral life‐history strategies showed that weedy corals generally increased their contributions to CCC over time while the contribution of competitive corals decreased. Shifts in contributions by stress‐tolerant and generalist corals to CCC were more variable across regions. The increasing frequency and intensity of disturbances under 21st century global change therefore has the potential to drive lower and more variable CCC because of the increasing dominance of weedy and some stress‐tolerant corals.

Coelomic Fluid Evaluation in Pisaster ochraceus Affected by Sea Star Wasting Syndrome: Evidence of Osmodysregulation, Calcium Homeostasis Derangement, and Coelomocyte Responses.

Sea Star Wasting Syndrome (SSWS) is one of the largest marine wildlife die-offs ever recorded, killing millions of sea stars from more than 20 Asteroid species from Alaska to Mexico from 2013 to 2015 from yet undetermined cause(s). Coelomic fluid surrounds the sea star's organs, playing critical roles in numerous systemic processes, including nutrient transportation and immune functions. Coelomocytes, which are cellular components of coelomic fluid and considered functionally equivalent to vertebrate leukocytes, are responsible for innate cell-mediated immunity. The objectives of this study were to (1) evaluate changes in coelomic fluid chemistry, coelomocyte counts, and cytology from ochre sea stars (Pisaster ochraceus) (n = 55) with clinical signs consistent with SSWS at varying intensity (SSWS score 1: n = 4, score 2: n = 2, score 3: n = 3, score 4: n = 18, score 5: n = 26) in comparison to coelomic fluid from clinically normal sea stars (n = 26) and to (2) correlate SSWS score with cellular and biochemical analytes. SSWS-affected sea stars had wider ranges of all electrolytes, except calcium; statistically significantly higher chloride, osmolality, and total protein; lower calcium; and higher coelomocyte counts when compared to clinically normal sea stars maintained under identical environmental conditions. Free and/or phagocytized bacteria were noted in 29% (16 of 55) coelomic fluid samples from SSWS-affected sea stars but were absent in clinically normal sea stars. SSWS score correlated significantly with increasing chloride concentration, osmolality, and coelomocyte counts. These chemistry and cytological findings in coelomic fluid of SSWS-affected sea stars provide insight into the pathophysiology of SSWS as these results suggest osmo- and calcium dysregulation, coelomocyte responses, and presumptive opportunistic bacterial infection in SSWS-affected sea stars. This information provides potential future research applications for the development of treatment strategies for sea stars in managed care and for understanding the complexity of various biochemical and cellular pathophysiological mechanisms involved in sea star wasting.