A scuticociliate causes mass mortality of Diadema antillarum in the Caribbean Sea.

Echinoderm mass mortality events shape marine ecosystems by altering the dynamics among major benthic groups. The sea urchin Diadema antillarum, virtually extirpated in the Caribbean in the early 1980s by an unknown cause, recently experienced another mass mortality beginning in January 2022. We investigated the cause of this mass mortality event through combined molecular biological and veterinary pathologic approaches comparing grossly normal and abnormal animals collected from 23 sites, representing locations that were either affected or unaffected at the time of sampling. Here, we report that a scuticociliate most similar to Philaster apodigitiformis was consistently associated with abnormal urchins at affected sites but was absent from unaffected sites. Experimentally challenging naïve urchins with a Philaster culture isolated from an abnormal, field-collected specimen resulted in gross signs consistent with those of the mortality event. The same ciliate was recovered from treated specimens postmortem, thus fulfilling Koch's postulates for this microorganism. We term this condition D. antillarum scuticociliatosis.

Current trends in patient-reported outcome measures for clavicle fractures: a focused systematic review of 11 influential orthopaedic journals.

BACKGROUND: Many patient-reported outcome measures (PROMs) have been used to follow clavicle fractures, providing an objective means to track outcomes. However, lack of standardization of PROM usage makes cross-study comparison difficult. Therefore, we reviewed articles on clavicle fractures from 11 of the most influential orthopedic journals to assess trends in PROM usage over time and based on geographic location. METHODS: A focused systematic review of 11 of the most influential orthopedic journals was performed using PubMed. All articles published between 1981 and 2020 with greater than 9 patients reporting clinical outcomes of clavicle fractures were included. For each article, patient demographics, treatment modality, geographic location, and outcome measures used were recorded. Temporal trends were identified using the Cochran-Armitage test for trend and linear regression. Pearson chi-square and Kruskal-Wallis tests were used to compare between journals, geographic location, study type, and fracture classification. RESULTS: From the initial literature search of 623 articles, 151 studies reporting on 15,853 primary clavicle fractures were included. Fractures of the middle one-third of the clavicle were most studied in the included literature (71%). Seventeen different PROMs were used, with an average of 1.6 outcome measures per study, and there was a significant increase in the number of PROMs used per article over time (P < .001). The Constant-Murley score was the most-reported outcome measure (44%) followed by the Disabilities of the Arm, Shoulder, and Hand score (27%), visual analog scale for pain (23%), and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES; 14%). There was a significant difference between the measures used based on geography (P = .002), the most notable being that North American authors use the ASES score more frequently. CONCLUSIONS: The use of PROMs in studies evaluating clavicle fracture treatment outcomes has increased over time, with recent studies reporting more PROMs than older studies, and there are notable differences in usage of the various scores based on geography and journal. Although there is no consensus on the most reliable PROM for assessing clavicle fractures, we recommend the use of at least 2 of the commonly reported PROMs in future studies to facilitate cross-study comparisons.

Arrested Sexual Development in Queen Conch (Lobatus gigas) Linked to Abnormalities in the Cerebral Ganglia.

In the Florida Keys, queen conchs (Lobatus gigas) occur in two spatially distinct regions: nearshore in habitats immediately adjacent to the shoreline and offshore in habitats along the reef tract south of the islands. Our previous research demonstrated that adult conchs nearshore are not reproductively active, showing deficiencies in their gonadal condition compared to their offshore counterparts. Because sexual development in gastropods is controlled by hormones secreted by the cerebral ganglia, we hypothesized that the reproductive deficiencies seen in nearshore queen conchs involved the cerebral ganglia. We collected nearshore and offshore adults and made histological comparisons of their gonads and cerebral ganglia. Our results confirmed that gonadal maturity was delayed and that gamete production was reduced in nearshore conchs compared to offshore animals. These gonadal deficiencies in nearshore conchs were associated with abnormal cerebral ganglion histology (i.e., significant hypertrophy of ganglion cells and significantly lower density of ganglion cells). In addition, the shells of nearshore conchs were significantly lighter, which is particularly consequential because shell formation in gastropods is also mediated by hormones secreted by the cerebral ganglia. Given these results, it is apparent that some yet unidentified factor(s) is interfering with hormone production in the cerebral ganglia, to the detriment of gonad development and shell formation.

Predator-prey interactions between the corallivorous snail Coralliophila abbreviata and the carnivorous deltoid rock snail Thais deltoidea.

Coral reefs in the Florida Keys have become highly degraded in recent decades, prompting efforts to reestablish populations of vital reef-accreting corals to restore reef structure and ecological function. However, predation on these corals by the corallivorous gastropod Coralliophila abbreviata has been a substantial and chronic impediment to these restoration efforts. We conducted laboratory experiments to determine whether Thais deltoidea, a carnivorous gastropod that commonly occurs with C. abbreviata, is a predator of C. abbreviata. We demonstrated that T. deltoidea readily preys upon C. abbreviata and preferentially targets smaller individuals, a foraging behavior that may optimize the energy gained due to reduced handling and consumption times. If this trophic relationship proves ecologically relevant, understanding the predator-prey dynamics between these species could ultimately aid in the development of a comprehensive coral reef restoration strategy for Florida.

Effects of mosquito control pesticides on competent queen conch (Strombus gigas) larvae.

Pesticides are applied seasonally in the Florida Keys to control nuisance populations of mosquitoes that pose a health threat to humans. There is, however, a need to investigate the effects of these pesticides on non-target marine organisms. We tested naled and permethrin, two mosquito adulticides used in the Keys, on a critical early life-history stage of queen conch (Strombus gigas). We conducted 12-h exposure experiments on competent (i.e., capable of undergoing metamorphosis) queen conch larvae using environmentally relevant pesticide concentrations. We found that there was little to no mortality and that the pesticides did not induce or interfere with metamorphosis. However, after introduction of a natural metamorphic cue (extract of the red alga Laurencia potei), a significantly greater proportion of larvae underwent metamorphosis in the pesticide treatments than in those with the alga alone. In addition to the morphogenetic pathway that induces metamorphosis when stimulated, there thus appears to be a regulatory pathway that enhances the response to metamorphic triggers, as suggested by the increased sensitivity of the queen conch larvae to the algal cue after pesticide exposure (i.e., the pesticides stimulated the regulatory pathway). The regulatory pathway probably plays a role in the identification of high-quality habitat for metamorphosis, as the increased response to the algal cue suggests. Aerial drift and runoff can carry these pesticides into nearshore waters, where they may act as a false signal of favorable conditions and facilitate metamorphosis in suboptimal habitat, thus adversely affecting recruitment in nearshore queen conch populations.

An angiographic and intravascular ultrasound study of the left anterior descending coronary artery in takotsubo cardiomyopathy.

The precise cause of takotsubo cardiomyopathy (TC) remains controversial. Plaque rupture with transient thrombotic occlusion of a transapical left anterior descending coronary artery (LAD) has been advanced as a potential mechanism. To explore this hypothesis, the investigators analyzed data from 11 patients prospectively enrolled in the Rhode Island Takotsubo Cardiomyopathy Registry who underwent coronary angiography and intravascular ultrasound evaluation of the LAD during their initial presentation. Despite the presence of nonobstructive coronary artery disease, no culprit lesion was identified in any patient. Similarly, the course of the LAD failed to account for the characteristic left ventricular apical ballooning seen in TC. In conclusion, an atherosclerotic coronary lesion in the LAD causing an aborted myocardial infarction may not be the primary underlying cause of TC, and nonobstructive coronary artery disease and TC may coexist without a direct causal association.

Predator-induced behavioral and morphological plasticity in the tropical marine Gastropod Strombus gigas.

Florida queen conch stocks once supported a significant fishery, but overfishing prompted the state of Florida to institute a harvest moratorium in 1985. Despite the closure of the fishery, the queen conch population has been slow to recover. One method used in the efforts to restore the Florida conch population has been to release hatchery-reared juvenile conch into the wild; however, suboptimal predator avoidance responses and lighter shell weights relative to their wild counterparts have been implicated in the high mortality rates of released hatchery juveniles. We conducted a series of experiments in which hatchery-reared juvenile conch were exposed to a predator, the spiny lobster (Panulirus argus), to determine whether they could develop behavioral and morphological characteristics that would improve survival. Experiments were conducted in tanks with a calcareous sand substrate to simulate a natural environment. Conditioned conch were exposed to caged lobsters while conch in the control tanks were exposed to empty cages. Conditioned conch moved significantly less and buried themselves more frequently than the naive control conch. Morphometric data indicated that the conditioned conch grew at a significantly slower rate than the naive conch, but the shell weights of the two groups were not significantly different. This implies that the conditioned conch had thicker or denser shells than the control group. As a result, the conditioned conch had significantly higher survival than naive conch in a subsequent predation experiment in which a lobster was allowed to roam free in each tank for 24 hours. In the future, the conditioning protocols documented in this study will be used to increase the survival of hatchery-reared conch in the wild.