As climate change progresses rapidly, biodiversity declines, and ecosystems shift, it is becoming increasingly difficult to document dynamic populations, track fluctuations, and predict responses to climate change. Concurrently, publicly available databases and tools are improving scientific accessibility, increasing collaboration, and generating more data than ever before. One of the most successful projects is iNaturalist, an AI-driven social network doubling as a public database designed to allow citizen scientists to report personal biodiversity reports with accuracy. iNaturalist is especially useful for the research of rare, dangerous, and charismatic organisms, but requires better integration into the marine system. Despite their abundance and ecological relevance, there are few long-term, high-sample datasets for jellyfish, which makes management difficult. To provide some high-sample datasets and demonstrate the utility of publicly collected data, we synthesized two global datasets for ten genera of jellyfishes in the order Rhizostomeae containing 8412 curated datapoints from both iNaturalist (n = 7807) and the published literature (n = 605). We then used these reports in conjunction with publicly available environmental data to predict global niche partitioning and distributions. Initial niche models inferred that only two of ten genera have distinct niche spaces; however, the application of machine learning-based random forest models suggests genus-specific variation in the relevance of abiotic environmental variables used to predict jellyfish occurrence. Our approach to incorporating reports from the literature with iNaturalist data helped evaluate the quality of the models and, more importantly, the quality of the underlying data. We find that free, accessible online data is valuable, yet subject to biases through limited taxonomic, geographic, and environmental resolution. To improve data resolution, and in turn its informative power, we recommend increasing global participation through collaboration with experts, public figures, and hobbyists in underrepresented regions capable of implementing regionally coordinated projects.

Jellyfishes of the order Rhizostomeae include ecologically and economically important species predisposed to forming massive aggregations. This study reports the first complete mitochondrial genome of two rhizostomes: Cephea cephea (Forsk & aring;l, 1775) and Mastigias albipunctata Stiasny, 1920. The linear mitochondrial genomes are 16,667bp and 16,707bp in length and 65.5% and 68.4% AT respectively; each comprises 15 protein-coding genes (PCGs; dpo, orf314, cox1-3, nd1-6, nd4L, atp6, atp8 and cytB), two ribosomal RNAs (16S and 12S rRNA), and two tRNAs (trnM and trnW). The phylogenetic analysis reveals strong support for monophyly of the suborder Kolpophorae and Cephea cephea of the infraorder Actinomyaria as sister to Krykomyaria which includes Mastigias.

Rhizostomeae (Scyphozoa) jellyfishes are widespread in neritic waters and include species of commercial importance in Asia. This group comprises jellyfish taxa that host endosymbiotic dinoflagellates of the family Symbiodiniaceae, which provide autotrophic benefits. Despite their value, limited molecular data for Japanese rhizostome taxa has hinder accurate taxonomic classification and interpretation of novel traits. This study combines molecular methods to provide the most complete understanding of molecular phylogenetic relations of Rhizostomeae jellyfishes while assessing the number of Symbiodiniaceae taxa that can be hosted in each species at the medusa level through a new method developed herein for tandem amplification of symbionts and host, validated with microscopy. We also evaluate which rhizostomes produce cassiosomes and whether Symbiodiniaceae are found in the core. Phylogenetic analysis of host mitochondrial (16S rRNA, COI) and nuclear (28S) gene regions of 18 medusae from five genera revealed: (1) Mastigias in Japanese waters corresponds to M. albipunctata ; (2) Cassiopea from Kagoshima likely represents an undescribed species, though Cassiopea xamachana may have been introduced; (3) Two cepheid species - Cephea cephea and Netrostoma setouchianum - occur in Japan; (4) Rhopilema esculentum , a commonly harvested species, is endemic to western Japan. Symbiotic Symbiodiniaceae ITS2 analysis identified three dominant genera ( Symbiodinium , Cladocopium , and Durusdinium ). More than one genus among these was found to be hosted in samples of the genera Mastigias and Cassiopea , indicating plasticity in symbiont association at both the taxon and individual medusa level. Microscopy confirmed cassiosome production exclusively in species examined of the suborder Kolpophorae: Cassiopea sp., N. setouchianum , and M. albipunctata , though absent in a juvenile M. albipunctata sample. Conversely, R. esculentum hosts Symbiodiniaceae but appears to lack the ability to produce cassiosomes. Overall, findings support the distinctive evolution of Symbiodiniaceae–Rhizostomeae symbiosis, the monophyly of the suborder Kolpophorae, and the synapomorphy of cassiosome production in Kolpophorae with onset likely influenced by developmental stage. Broader taxon sampling, especially within Dactyliophorae, will provide further clues on the functional evolution and cellular organization underlying photoendosymbiosis and cassiosome production in these medusozoans.

Gastrointestinal parasites have been reported in wild Sunda pangolins ( Manis javanica ), but the clinical significance of such detections is often unknown. This report describes pathological lesions in the stomachs of two dead wild Sunda pangolins caused by Gendrespirura sp.. Gross and histopathological examination showed gastritis and hyperkeratosis in infected animals. Morphological identification confirmed the presence of Gendrespirura sp., and molecular analysis revealed a close phylogenetic relationship with the genus Gendrespirura, supporting placement within the family Habronematidae. This report highlights the pathological significance of parasite infections in wild pangolins in Singapore, further advancing our understanding of the natural biology and parasitology of wild Sunda pangolins, and the effects of these infections on the health and conservation of this critically endangered species.

Mastigias jellyfish (“tako kurage”) have been reported throughout littoral Japan for over a century, historically identified by morphology alone as Mastigias papua. Molecular resolution of the genus in 2018 revealed three geographically structured clades and suggested Japanese populations instead belong to M. albipunctata, but subsequent morphology-only studies of Japanese specimens have continued to apply the M. papua designation, leaving species identity unresolved across much of the species’ Japanese range. Here, we use cytochrome c oxidase subunit I (COI), combining published GenBank sequences with two newly collected specimens from Okinawa, the southernmost extent reported in Japan. Maximum-likelihood and Bayesian phylogenetic reconstruction recovered three reciprocally monophyletic clades consistent with previous molecular work, with all Japanese sequences, from Sukumo Bay (Shikoku Island) to Okinawa Island, falling within the M. albipunctata clade. Morphological comparison against published diagnostic characters showed consistency with this identification. These results indicate that Mastigias populations in Japan are consistently identified as M. albipunctata, while highlighting the value of molecular analysis in tandem with morphology-based identification approaches.