Etelis boweni sp. nov., a new cryptic deepwater eteline snapper from the Indo-Pacific (Perciformes: Lutjanidae).

A new species of Etelis is described based on 16 specimens collected from the Red Sea and Western Australia, with confirmed genetic records throughout the Indo-West Pacific. It is similar to and was often misidentified as Etelis carbunculus Cuvier, with both species sharing the diagnostic character of low number of developed gill rakers. Nonetheless, the two species are genetically divergent and differ morphologically in adult body length; proportions of eye, snout, cheek and caudal fin; shape of head, opercular spine and sagittal otolith; and coloration of the tip of the upper caudal fin. Etelis boweni has a wide Indo-west Pacific distribution that largely overlaps with E. carbunculus, and the two species are often caught on the same fishing line.

Intraprocedural high-degree atrioventricular block or complete heart block in transcatheter aortic valve replacement recipients with no prior intraventricular conduction disturbances.

BACKGROUND: Conduction disturbances are the most frequent complication of transcatheter aortic valve replacement (TAVR). However, no data exists regarding the outcomes of intraprocedural high-degree atrioventricular block (HAVB) or complete heart block (CHB) in patients without previous conduction disturbances. OBJECTIVES: The aim of this study was to evaluate the outcomes of intraprocedural-HAVB/CHB in patients without previous intraventricular conduction disturbances. METHODS: The occurrence of intraprocedural-HAVB/CHB was assessed in 676 consecutive patients undergoing TAVR, and two groups were established according to its duration: persistent-HAVB/CHB (PHAVB/CHB) and transient-HAVB/CHB (THAVB/CHB), not present at the end of the procedure. RESULTS: Intraprocedural-HAVB/CHB occurred in 50 patients (7.4%), being persistent in 32 (64.0%), and transient in 18 (36.0%). The use of Medtronic Corevalve Revalving System (MCRS) and a greater oversizing of the valve increased the risk of intraprocedural-HAVB/CHB (p < 0.001). Permanent pacemaker implantation (PPI) was more frequent in the PHAVB/CHB than in the THAVB/CHB group (96.9% vs. 33.3%; p < 0.001). At 1-month follow-up, the PHAVB/CHB group showed a 98% ventricular pacing rate (VPR) compared to 16% in the THAVB/CHB group (p < 0.001), and similar VPR were observed at 1-year follow-up (98% vs. 37%, p < 0.001). Left ventricular ejection fraction (LVEF) decreased at 1-year follow-up in patients with PHAVB/CHB (-3.9 ± 1.8%, p = 0.003). CONCLUSIONS: In TAVR recipients with no prior intraventricular conduction disturbances, intraprocedural-HAVB/CHB occurred in 7.4% of cases. HAVB/CHB was persistent in most cases and determined a high rate of PPI post-TAVR. Very high VPR at 1- and 12-month follow-up were observed, which in turn was associated with a negative effect on LVEF. These results support early PPI and close follow-up in patients developing intraprocedural-PHAVB/CHB.

The projected timing of climate departure from recent variability.

Ecological and societal disruptions by modern climate change are critically determined by the time frame over which climates shift beyond historical analogues. Here we present a new index of the year when the projected mean climate of a given location moves to a state continuously outside the bounds of historical variability under alternative greenhouse gas emissions scenarios. Using 1860 to 2005 as the historical period, this index has a global mean of 2069 (±18 years s.d.) for near-surface air temperature under an emissions stabilization scenario and 2047 (±14 years s.d.) under a 'business-as-usual' scenario. Unprecedented climates will occur earliest in the tropics and among low-income countries, highlighting the vulnerability of global biodiversity and the limited governmental capacity to respond to the impacts of climate change. Our findings shed light on the urgency of mitigating greenhouse gas emissions if climates potentially harmful to biodiversity and society are to be prevented.

Molecular Phylogeny Demonstrates the Need for Taxonomic Reconsideration of Species Diversity of the Hydrocoral Genus Millepora (Cnidaria: Hydrozoa) in the Pacific.

Millepora (Cnidaria: Hydrozoa: Milleporidae) spp. are distributed throughout shallow subtropical and tropical marine environments in the Indo-Pacific and Caribbean-Atlantic, and have traditionally been identified using pore characteristics and colony form. Until now, representatives of Millepora spp. on the island of Okinawa-jima, Japan, have been divided into five species; three branching species (Millepora intricata, M. tenera, M. dichotoma), one species with plate-like morphology (M. platyphylla), and one encrusting species (M. exaesa). There have been only a few reports from the Indo-Pacific that have studied the genetic diversity within Millepora spp., although phylogenetic analyses in the Caribbean-Atlantic have proven useful in delimiting closely-related species, while demonstrating that morphologically-based identification systems may have problems. In the present study, we sought to clarify taxonomic confusion of Millepora spp. in the Pacific by using sequence data of the ribosomal internal transcribed spacer (ITS-rDNA) of specimens from Okinawa, Japan and other localities (Johnston Atoll, Great Barrier Reef). Four separate clades were recovered from the ITS-rDNA analyses. Although we examined specimens of all three branching Millepora spp. previously reported from Okinawa-jima Island, in our phylogenetic analyses they were concentrated within a single clade, with only three specimens in other clades. Encrusting Millepora specimens were found within all clades, although it should be noted all species initially start as encrusting forms, and plate-like specimens were found within three clades. Our data also point to the existence of a previously unknown lineage within Millepora characterized by its ability to overgrow live scleractinian corals.

Global divergence of the human follicle mite Demodex folliculorum: Persistent associations between host ancestry and mite lineages.

Microscopic mites of the genus Demodex live within the hair follicles of mammals and are ubiquitous symbionts of humans, but little molecular work has been done to understand their genetic diversity or transmission. Here we sampled mite DNA from 70 human hosts of diverse geographic ancestries and analyzed 241 sequences from the mitochondrial genome of the species Demodex folliculorum. Phylogenetic analyses recovered multiple deep lineages including a globally distributed lineage common among hosts of European ancestry and three lineages that primarily include hosts of Asian, African, and Latin American ancestry. To a great extent, the ancestral geography of hosts predicted the lineages of mites found on them; 27% of the total molecular variance segregated according to the regional ancestries of hosts. We found that D. folliculorum populations are stable on an individual over the course of years and that some Asian and African American hosts maintain specific mite lineages over the course of years or generations outside their geographic region of birth or ancestry. D. folliculorum haplotypes were much more likely to be shared within families and between spouses than between unrelated individuals, indicating that transmission requires close contact. Dating analyses indicated that D. folliculorum origins may predate modern humans. Overall, D. folliculorum evolution reflects ancient human population divergences, is consistent with an out-of-Africa dispersal hypothesis, and presents an excellent model system for further understanding the history of human movement.

Phylogeny of deepwater snappers (Genus Etelis) reveals a cryptic species pair in the Indo-Pacific and Pleistocene invasion of the Atlantic.

Evolutionary genetic patterns in shallow coastal fishes are documented with dozens of studies, but corresponding surveys of deepwater fishes (>200m) are scarce. Here we investigate the evolutionary history of deepwater snappers (genus Etelis), comprised of three recognized Indo-Pacific species and one Atlantic congener, by constructing a phylogeny of the genus with two mtDNA loci and two nuclear introns. Further, we apply range-wide Indo-Pacific sampling to test for the presence and distribution of a putative cryptic species pair within E. carbunculus using morphological analyses and mtDNA cytochrome b sequences from 14 locations across the species range (N=1696). These analyses indicate that E. carbunculus is comprised of two distinct, non-interbreeding lineages separated by deep divergence (d=0.081 in cytochrome b). Although these species are morphologically similar, we identified qualitative differences in coloration of the upper-caudal fin tip and the shape of the opercular spine, as well as significant differences in adult body length, body depth, and head length. These two species have overlapping Indo-Pacific distributions, but one species is more widespread across the Indo-Pacific, whereas the other species is documented in the Indian Ocean and Western Central Pacific. The dated Etelis phylogeny places the cryptic species divergence in the Pliocene, indicating that the biogeographic barrier between the Indian and Pacific Oceans played a role in speciation. Based on historic taxonomy and nomenclature, the species more widespread in the Pacific Ocean is E. carbunculus, and the other species is previously undescribed (referred to here as E. sp.). The Atlantic congener E. oculatus has only recently (∼0.5Ma) diverged from E. coruscans in the Indo-Pacific, indicating colonization via southern Africa. The pattern of divergence at the Indo-Pacific barrier, and Pleistocene colonization from the Indian Ocean into the Atlantic, is concordant with patterns observed in shallow coastal fishes, indicating similar drivers of evolutionary processes.

Multilocus evidence for globally distributed cryptic species and distinct populations across ocean gyres in a mesopelagic copepod.

Zooplanktonic taxa have a greater number of distinct populations and species than might be predicted based on their large population sizes and open-ocean habitat, which lacks obvious physical barriers to dispersal and gene flow. To gain insight into the evolutionary mechanisms driving genetic diversification in zooplankton, we developed eight microsatellite markers to examine the population structure of an abundant, globally distributed mesopelagic copepod, Haloptilus longicornis, at 18 sample sites across the Atlantic and Pacific Oceans (n = 761). When comparing our microsatellite results with those of a prior study that used a mtDNA marker (mtCOII, n = 1059, 43 sample sites), we unexpectedly found evidence for the presence of a cryptic species pair. These species were globally distributed and apparently sympatric, and were separated by relatively weak genetic divergence (reciprocally monophyletic mtCOII lineages 1.6% divergent; microsatellite FST ranging from 0.28 to 0.88 across loci, P < 0.00001). Using both mtDNA and microsatellite data for the most common of the two species (n = 669 for microsatellites, n = 572 for mtDNA), we also found evidence for allopatric barriers to gene flow within species, with distinct populations separated by continental landmasses and equatorial waters in both the Atlantic and Pacific Ocean basins. Our study shows that oceanic barriers to gene flow can act as a mechanism promoting allopatric diversification in holoplanktonic taxa, despite the high potential dispersal abilities and pelagic habitat for these species.

"Inherited cardiovascular disease mindset" can identify concealed inherited conditions at cardio-oncology evaluation: An opportunistic screening.

INTRODUCTION: Baseline cardiovascular (CV) risk stratification is recommended in all cancer patients. Integrating all clinical information (personal/family history, ECG and echocardiogram) can properly identify high-risk patients. We aimed to evaluate the concealed inherited CV conditions detected in mandatory CV screening performed at a Cardio-Oncology Unit. METHODS: retrospective study of all consecutive cancer patients referred to the Cardio-Oncology Unit for CV evaluation (2020-2023). Inherited CV conditions diagnosis and genetic testing was performed according to guidelines. RESULTS: 1984 cancer patients underwent CV screening. Sanger sequencing was indicated in 1 patient, excluding the genetic family disease. NGS sequencing was performed in 11 cancer patients with normal left ventricular ejection fraction (LVEF): 2 due to aortic syndrome evaluation (identifying 1 vascular Ehrler-Danlos syndrome due to COL3A1 p.Arg242Ter), 4 channelopathies (2 Long QT syndrome and 2 Brugada's), 4 hypertrophic cardiomyopathies and 1 non-dilated left ventricular cardiomyopathy (NDLVC). Among the 12 patients with reduced LVEF, one was diagnosed with NDLVC, and chemotherapy-induced dilated cardiomyopathy was only ascribable in 3 of them. CONCLUSION: Integrating clinical information at mandatory baseline CV toxicity risk cardio-oncology evaluation, can identify high-risk cancer patients with concealed inherited conditions. Keeping an "inherited cardiovascular disease-oriented mindset" to implement opportunist screenings is encouraged.

Left and Right Ventricular Longitudinal Systolic Function Following Aortic Valve Replacement in the PARTNER 2 Trial And Registry.

AIMS: Evaluation of left and right ventricular longitudinal systolic function may enhance risk stratification following aortic valve replacement (AVR). The study objective was to evaluate the changes in left and right ventricular longitudinal systolic function and RV-pulmonary artery (RV-PA) coupling from baseline to 30-days and 1-year after aortic valve replacement (AVR). METHODS AND RESULTS: LV longitudinal strain (LS), tricuspid annulus plane systolic excursion (TAPSE), and RV-PA coupling were evaluated in patients from the PARTNER-2A surgical AVR (SAVR) arm (n=985) and from the PARTNER-2 SAPIEN-3 registry (n=719). TAPSE and RV-PA coupling decreased significantly following SAVR, but remained stable following TAVR. Lower LV LS, TAPSE, or RV-PA coupling at baseline were associated with increased risk of the composite of death, hospitalization, and stroke at 5-years (Adjusted-HRs for LV LS<15%: 1.24 95%CI 1.05-1.45, p=0.001; TAPSE<14mm: 1.44 95%CI 1.21-1.73, p<0.001; RV/PA coupling<0.55mm/mmHg: 1.32 95% CI 1.07-1.63, p=0.011). Reduced TAPSE at baseline was the most powerful predictor of the composite endpoint at 5-years. Patients with LV ejection fraction <50% at baseline had increased risk of the primary endpoint with SAVR (HR: 1.34, 95%CI 1.08-1.68, p=0.009) but not with TAVR (HR: 1.12, 95%CI 0.88-1.42). Lower RV-PA coupling at 30-days showed the strongest association with cardiac mortality. CONCLUSION: SAVR but not TAVR was associated with a marked deterioration in RV longitudinal systolic function and RV-PA coupling. Lower TAPSE and RV-PA coupling at 30-days were associated with inferior clinical outcomes at 5-years. In patients with LVEF<50%, TAVR was associated with superior 5-year outcomes.

Current status of transcatheter mitral valve replacement: systematic review and meta-analysis.

Introduction: Mitral Regurgitation (MR) has a strong impact on quality of life and on mid-term survival. Transcatheter mitral valve replacement (TMVR) is rapidly expanding and a growing number of studies have been published recently. Methods: A systematic review of studies reporting on clinical data for patients with symptomatic severe MR undergoing TMVR was performed. Early- and mid-term outcomes (clinical and echocardiographic) were evaluated. Overall weighted means and rates were calculated. Risk ratios or mean differences were calculated for pre- and post-procedural comparisons. Results: A total of 12 studies and 347 patients who underwent TMVR with devices clinically available or under clinical evaluation were included. Thirty-day mortality, stroke and major bleeding rates were 8.4%, 2.6%, and 15.6%, respectively. Pooled random-effects demonstrated a significant reduction of ≥ grade 3+ MR (RR: 0.05; 95% CI: 0.02-0.11; p < 0.001) and in the rates of patients in NYHA class 3-4 after the intervention (RR: 0.27; 95% CI: 0.22-0.34; p < 0.001). Additionally, the pooled fixed-effect mean difference for quality of life based on the KCCQ score yielded an improvement in 12.9 points (95% CI:7.4-18.4, p < 0.001), and exercise capacity improved by a pooled fixed-effect mean difference of 56.8 meters in the 6-minute walk test (95% CI 32.2-81.3, p < 0.001). Conclusions: Among 12 studies and 347 patients comprising the updated evidence with current TMVR systems there was a statistically significant reduction in ≥ grade 3+ MR and in the number of patients exhibiting poor functional class (NYHA 3 or 4) after the intervention. Overall rate of major bleeding was the main shortcoming of this technique.

Leaving obstacles aside: Antegrade paravalvular leakage closure after transcatheter aortic valve replacement.

Paravalvular leakage (PVL) is yet a potential and serious complication after transcatheter aortic valve replacement. Percutaneous PVL closure may be the treatment of choice upon failure of balloon postdilation in patients with excessive surgical risk. If the retrograde approach fails, an antegrade strategy might provide the solution.

Early and mid-term outcomes of transcatheter tricuspid valve repair: systematic review and meta-analysis of observational studies.

INTRODUCTION AND OBJECTIVES: Severe tricuspid regurgitation (TR) is associated with poor prognosis when left untreated, and a growing number of studies on transcatheter tricuspid valve repair (TTVr) have been published over the last few months. METHODS: We performed a comprehensive systematic review of published literature providing clinical data on TTVr for patients with significant TR. Early and mid-term clinical and echocardiographic outcomes were evaluated. Risk ratios (RR) or mean differences (MD) were obtained when comparing pre- and postprocedural data. A sensitivity analysis was also performed according to the main approach for repair (edge-to-edge vs annuloplasty). RESULTS: A total of 19 studies (all observational or single-arm trials) and 991 patients who underwent isolated TTVr were included. Thirty-day mortality and stroke rates were 2.8% and 0.2%, respectively. Pooled random-effects resulted in a significant reduction of ≥ severe TR (RR, 0.33; 95%CI, 0.26-0.42; P < .001), vena contracta width (MD, 5.9mm; 95%CI, 4-7.9; P <.001), right ventricular end-diastolic diameter (MD, 3.5mm; 95%CI, 2.5-4.5; P <.001), and New York Heart Association (NYHA) class III or IV at last follow-up (RR, 0.32; 95%CI, 0.27-0.37; P <.001). Bleeding complications and residual ≥ severe TR were numerically higher in the annuloplasty-like group compared with edge-to-edge repair (13.3% vs 3.8% for bleeding and 40.4% vs 27.9% for residual severe TR). CONCLUSIONS: Among 991 patients comprising the early experience for several TTVr devices, there was a statistically significant reduction in ≥ severe TR, NYHA class III-IV, vena contracta width and right ventricular end-diastolic diameter after TTVr. Thus far, the edge-to-edge approach seems to be associated with a better safety profile.

Anatomical Changes after Transcatheter Edge-to-Edge Repair in Functional MR According to MitraClip Generation.

BACKGROUND: The use of mitral transcatheter edge-to-edge repair (TEER) is rapidly increasing. Anatomical changes have been described after TEER with the MitraClip system in patients with functional mitral regurgitation (MR), although no study has yet evaluated such anatomical impacts in patients treated with the G4 MitraClip generation. METHODS: This research constituted a prospective, single-center, observational study including consecutive patients with functional MR. Mitral three-dimensional images were obtained transesophageally with echocardiography before and immediately after TEER. Patients receiving the late-generation (G4) system were compared to those receiving early-generation systems. RESULTS: A total of 116 functional MR patients were evaluated, and 40 (34.5%) and 76 (65.5%) received a late-generation (G4) or early-generation device system, respectively. The baseline clinical and echocardiographic features were well-balanced between the groups. Overall, there was a significant reduction in mitral annular size after the intervention, and greater reductions in the anteroposterior diameter (4 mm vs. 3.54 mm, p = 0.03), annular perimeter (11.07 mm vs. 5.29 mm for 3D-perimeter, p = 0.001), and annular area (1.29 cm2 vs. 1.03 cm2, p = 0.002) were found for patients receiving the late G4 device generation compared to the early-generation systems. CONCLUSIONS: In patients with functional MR, we observed significant changes in mitral valve anatomy with a reduction in anteroposterior diameter, valve perimeter, and area. In our cohort, the extent of those changes was greater with the use of the new-generation G4 MitraClip system compared to prior device generations.

Percutaneous Transcatheter Edge-to-Edge Mitral Valve Repair With MitraClip System in the Era of G4.

The use of transcatheter edge-to-edge mitral valve repair (TEER) in symptomatic patients with severe mitral regurgitation (MR) has dramatically increased over the last few years. Current guidelines consider TEER as a reasonable option in symptomatic patients with primary or chronic secondary severe MR with high or prohibitive surgical risk and favorable anatomy. However, several anatomical and morphological mitral features have restricted the use of this mini-invasive technique in its early experience. The latest fourth generation (G4) of the MitraClip system has been recently introduced and includes the possibility of independent leaflet grasping and 4 different sizes. This technical update offers the possibility of selecting and combining multiple devices for complex mitral valve anatomies and challenging procedures, which helps expand the applications of TEER. The present review describes the potential advantages and the help of the MitraClip G4 devices to overcome various anatomic and morphologic issues in challenging cases with complex primary and secondary MR procedures.

Confirmation of Aortic Stenosis Severity in Case of Discordance Between Aortic Valve Area and Gradient.

In this report, we illustrate the different flow-gradient patterns of aortic stenosis associated with discordant grading of stenosis severity at transthoracic echocardiography (TTE). The discordance among TTE parameters (mean gradient and aortic area) can be reconciled and true severity can be confirmed by ruling out potential measurements errors and by using multimodality imaging. (Level of Difficulty: Advanced.).

Transcatheter tricuspid valve interventions: Current status and future perspectives.

The development of transcatheter therapies to treat valvular heart diseases has changed the rules of the game, particularly in the case of aortic stenosis and mitral regurgitation. In the last years, the tricuspid valve has also been the focus of these percutaneous techniques for several reasons: (1) tricuspid regurgitation is a frequent disease associated with poor clinical outcomes in spite of medical treatment, leading to end-stage right ventricular heart failure, (2) surgical tricuspid valve repair or replacement has been the treatment of choice for patients with tricuspid valve disease, but high mortality rates for isolated surgical tricuspid valve intervention have been reported in the literature, and (3) most patients with tricuspid pathology are ultimately denied cardiac surgery because of their comorbidity burden. Thus, in this context the development of less invasive catheter-based therapies would be of high clinical relevance. The present review provides an overview regarding the framework of chronic tricuspid regurgitation transcatheter therapeutic options, summarizes the transcatheter systems under clinical use or clinical evaluation with their technical features, and describes the updated current evidence in this challenging and evolving field.

Different Phenotypes in Monozygotic Twins, Carriers of the Same Pathogenic Variant for Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a monogenic disease with autosomal dominant inheritance. Genotype−phenotype relationships are complex, with variable penetrance even within the same family. The involvement of other modulating genetic and environmental factors is unknown. We aimed to analyze the HCM in monozygotic twins, carriers of the same founder pathogenic variant MYBPC3 p.G263*. The relationship was verified using the PowerPlex 16 HS System kit. Phenotypic differences and environmental differences (overloading conditions, coexistence and location, lifestyle, sport, and intensity) were analyzed. Three pairs of twins genetically identical for all markers and carriers of MYBPC3 G263* were identified. No environmental differences were identified. One of the 89-year-old twins had symptomatic severe obstructive HCM that required septal ablation, while her twin has remained asymptomatic with mild phenotype >80 years. A 49-year-old twin had a severe phenotype of obstructive HCM and pending myectomy, while his twin had a mild asymptomatic phenotype. In the last pair of twins, one presented a much larger left ventricular hypertrophy than his identical twin. In summary, we present three pairs of HCM twin patients sharing not only the genetic cause of the inherited disease but the entire genetic background. Despite identical genetic information and the absence of other known clinical, environmental, or lifestyle differences, the severity of the HCM phenotype is strikingly different. These unexplained differences should prompt the study of other unknown modulating factors, either epigenetic or environmental.

Limited genomic reconstruction of SARS-CoV-2 transmission history within local epidemiological clusters.

A detailed understanding of how and when severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission occurs is crucial for designing effective prevention measures. Other than contact tracing, genome sequencing provides information to help infer who infected whom. However, the effectiveness of the genomic approach in this context depends on both (high enough) mutation and (low enough) transmission rates. Today, the level of resolution that we can obtain when describing SARS-CoV-2 outbreaks using just genomic information alone remains unclear. In order to answer this question, we sequenced forty-nine SARS-CoV-2 patient samples from ten local clusters in NW Spain for which partial epidemiological information was available and inferred transmission history using genomic variants. Importantly, we obtained high-quality genomic data, sequencing each sample twice and using unique barcodes to exclude cross-sample contamination. Phylogenetic and cluster analyses showed that consensus genomes were generally sufficient to discriminate among independent transmission clusters. However, levels of intrahost variation were low, which prevented in most cases the unambiguous identification of direct transmission events. After filtering out recurrent variants across clusters, the genomic data were generally compatible with the epidemiological information but did not support specific transmission events over possible alternatives. We estimated the effective transmission bottleneck size to be one to two viral particles for sample pairs whose donor-recipient relationship was likely. Our analyses suggest that intrahost genomic variation in SARS-CoV-2 might be generally limited and that homoplasy and recurrent errors complicate identifying shared intrahost variants. Reliable reconstruction of direct SARS-CoV-2 transmission based solely on genomic data seems hindered by a slow mutation rate, potential convergent events, and technical artifacts. Detailed contact tracing seems essential in most cases to study SARS-CoV-2 transmission at high resolution.

Exploring the trends of adaptation and evolution of sclerites with regards to habitat depth in sea pens.

Octocorals possess sclerites, small elements comprised of calcium carbonate (CaCO3) that are important diagnostic characters in octocoral taxonomy. Among octocorals, sea pens comprise a unique order (Pennatulacea) that live in a wide range of depths. Habitat depth is considered to be important in the diversification of octocoral species, but a lack of information on sea pens has limited studies on their adaptation and evolution across depth. Here, we aimed to reveal trends of adaptation and evolution of sclerite shapes in sea pens with regards to habitat depth via phylogenetic analyses and ancestral reconstruction analyses. Colony form of sea pens is suggested to have undergone convergent evolution and the loss of axis has occurred independently across the evolution of sea pens. Divergences of sea pen taxa and of sclerite forms are suggested to depend on habitat depths. In addition, their sclerite forms may be related to evolutionary history of the sclerite and the surrounding chemical environment as well as water temperature. Three-flanged sclerites may possess the tolerance towards the environment of the deep sea, while plate sclerites are suggested to be adapted towards shallower waters, and have evolved independently multiple times. The common ancestor form of sea pens was predicted to be deep-sea and similar to family Pseudumbellulidae in form, possessing sclerites intermediate in form to those of alcyonaceans and modern sea pens such as spindles, rods with spines, and three-flanged sclerites with serrated edges sclerites, as well as having an axis and bilateral traits.