Invertebrates

Newton, Alisa L.; Smolowitz, Roxanna

doi:10.1016/b978-0-12-805306-5.00041-9

Cited by 15 publications

(12 citation statements)

References 166 publications

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“…Other proposed mechanisms of wasting, including repeated [ 9 ] and monotonic [ 10 ] temperature excursions, high pCO 2 conditions [ 11 ], and low precipitation [ 5 ] have all been hypothesized to influence SSWD. SSWD is not associated with any known eukaryotic microorganism nor bacterium [ 4 , 5 , 12 , 13 , 14 ]. Microbiome studies during wasting progression suggest a progressive enrichment of copiotrophic bacteria on surfaces and within tissues [ 8 , 12 , 14 ] but none appear distinct only to affected specimens.…”

Section: Introductionmentioning

confidence: 99%

Virome Variation during Sea Star Wasting Disease Progression in Pisaster ochraceus (Asteroidea, Echinodermata)

Hewson

Aquino

DeRito

2020

Viruses

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Sea star wasting disease (SSWD) is a condition that has affected asteroids for over 120 years, yet mechanistic understanding of this wasting etiology remains elusive. We investigated temporal virome variation in two Pisaster ochraceus specimens that wasted in the absence of external stimuli and two specimens that did not experience SSWD for the duration of our study, and compared viromes of wasting lesion margin tissues to both artificial scar margins and grossly normal tissues over time. Global assembly of all SSWD-affected tissue libraries resulted in 24 viral genome fragments represented in >1 library. Genome fragments mostly matched densoviruses and picornaviruses with fewer matching nodaviruses, and a sobemovirus. Picornavirus-like and densovirus-like genome fragments were most similar to viral genomes recovered in metagenomic study of other marine invertebrates. Read recruitment revealed only two picornavirus-like genome fragments that recruited from only SSWD-affected specimens, but neither was unique to wasting lesions. Wasting lesion margin reads recruited to a greater number of viral genotypes (i.e., richness) than did either scar tissue and grossly normal tissue reads. Taken together, these data suggest that no single viral genome fragment was associated with SSWD. Rather, wasting lesion margins may generally support viral proliferation.

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Section: Introductionmentioning

confidence: 99%

Virome Variation during Sea Star Wasting Disease Progression in Pisaster ochraceus (Asteroidea, Echinodermata)

Hewson

Aquino

DeRito

2020

Viruses

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“…Culture of coelomic fluid was beyond the scope of this study and not attempted. The basophilic and proteinaceous material as well as the presumptive cholesterol crystals noted on cytology are probably due to apoptosis or necrosis as described by metatranscriptomic analysis (52) and histopathology (16) in SSWSaffected sea stars.…”

Section: Sea Star Wasting Syndrome-affected Sea Stars Show Active Celmentioning

confidence: 75%

“…If sea stars are truly becoming hyperosmotic to seawater by a yet unknown mechanism or cumulative mechanisms, this could explain why relatively hypoosmotic seawater could penetrate tissues and cause biochemical homoeostatic imbalances as seen in SSWS. Histopathology of sea stars with clinical signs consistent with SSWS showed extensive necrosis, epidermal ulceration, and dermal separation (16). In a study with ochre sea stars exposed to changes in salinity, coelomic fluid chloride concentrations approximated those of seawater, thus suggesting sea stars may not actively regulate chloride homeostasis (27).…”

Section: Dysregulation Of Critical Biochemical Regulatory Processes Amentioning

confidence: 96%

“…The progression of clinical observations can be rapid, typically leading to death within days (15). Histologically, wasting sea stars consistently exhibit epidermal degeneration, necrosis, and ulceration with dermal separation, necrosis, and inflammation (16). The etiology for these histological changes has not been determined to date.…”

Section: Introductionmentioning

confidence: 99%

“…For this reason, we have chosen to use the terminology Sea Star Wasting Syndrome rather than Sea Star Wasting Disease as it was initially referred to in previous publications by various authors (11,12). Due to limited types of tissue reactions to pathogens and other stressors in echinoderms, various disease processes reportedly result in similar clinical and histopathological manifestations (16). The ultimate cause(s) of the 2013-2015 SSWS event as well as most historical and more recent observations of sea star wasting in various geographical areas are still unknown.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

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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 Wahltinez et al. Wasting Sea Star Coelomic Fluid 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.

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