Back

Zootaxa

Magnolia Press

Preprints posted in the last 90 days, ranked by how well they match Zootaxa's content profile, based on 10 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.

1
Systematic revision of the suborder Astrophorina (Porifera: Demospongiae) in the temperate Northeast Pacific

Turner, T. L.

2026-06-26 zoology 10.64898/2026.06.22.733819 medRxiv
Top 0.1%
27.2%
Show abstract

This study presents a systematic revision of the suborder Astrophorina for the temperate Pacific coast of the United States and Canada. Major findings include a reduction in the number of species previously thought to range into the region from Japan; validation of most Geodia species erected by Lendenfeld (1910), which were later synonymized by de Laubenfels (1932); the formal description of 10 new species (Poecillastra alaskensis sp. nov., Vulcanella explorata sp. nov., Vulcanella rupta sp. nov., Stelletta cardenasi sp. nov., Stelletta nicolenya sp. nov., Stelletta limuwensis sp. nov., Dercitus (Stoeba) giveni sp. nov., Penares anyapax sp. nov., Penares foxi sp. nov., and Thenea diastra sp. nov.); and one new combination, Penares orientalis comb. nov. Extensive SCUBA-based collection efforts yielded new samples for 11 of the 26 species identified in the region, which enabled an integrative taxonomic approach that combined field photography, fresh material for DNA sequencing, and improved characterization of species ranges and morphological variability in previously described taxa. Illumina sequencing generated complete nuclear ribosomal haplotypes for five species, while Sanger sequencing of the 28S and cox1 loci placed 20 of the 26 species within molecular phylogenies. The use of very short "mini-barcode" amplicons also enabled sequence recovery from historic type specimens up to 137 years old. This study additionally reports the discovery of sponge grounds of abundant, large Geodia at diving depths in Southern California. Together, these results substantially advance our understanding of global astrophorid diversity and systematics, and the biogeography of sponge diversity in the Northeast Pacific. Note about species names: this pre-print is not intended to be a publication of the associated species names for the purposes of zoological nomenclature.

2
Molecular and Morphological Evidence Reveals Cryptonema producta in Shui Hau, Hong Kong, Previously Misidentified as Anomalocardia flexuosa

Lam, H.; Lin, S.; Xu, Z.; Yau, C. S. T.; Wu, L.

2026-05-18 zoology 10.64898/2026.05.14.725093 medRxiv
Top 0.1%
3.4%
Show abstract

For over four decades, the bivalve Anomalocardia flexuosa has been recorded in Hong Kong coastal waters. However, the known native distribution of this heavily exploited commercial species is restricted to the Atlantic coast of South America, raising questions about the biogeographical validity of the Hong Kong populations. By employing an integrative taxonomic approach combining morphological re-evaluations and molecular phylogenetic analysis of the COI gene, we confirm that the species in Shui Hau, Hong Kong, China, has been historically misidentified. The population belongs to Cryptonema producta (syn. Anomalocardia producta).

3
Integrative taxonomy of Trichiurus (Scombriformes: Trichiuridae) reveals a new cutlassfish species from Java, Indonesia

Wu, T.; Li, C.

2026-05-08 zoology 10.64898/2026.05.05.722933 medRxiv
Top 0.1%
3.0%
Show abstract

The genus Trichiurus is the most economically valuable fish in the family Trichiuridae, currently recognized to include 10 valid species. However, historically numerous morphologically similar congeners have been erroneously assigned as synonyms or subspecies of T. lepturus. In this study, we examined 16 hairtail specimens collected from the southern waters of Java Island, Indonesia. Integrated morphological and mitochondrial phylogenetic analyses (COX1 and 16S rRNA), compared against global Trichiurus sequences, revealed that these specimens form an independent lineage that diverged early from other congeners. Consequently, we describe this lineage as a previously undescribed cryptic species. Diagnostic characters include: first anal-fin spine below 36th-37th dorsal-fin rays; anus below 35th-36th dorsal-fin rays; anteriormost tip of supraoccipital well posterior to posterior distal margin of eye; anterior margin of the pectoral-fin spine non-serrated; fangs on both jaws with barb-like processes; upper jaw long, mean 16.6% (15.5-17.6%) of preanal length; snout short, 12.0% (10.9-13.1%) of preanal length; eye small, diameter 5.3% (4.3-5.7%) of preanal length; and absence of hyperostosis on dorsal cranium. We herein propose the name Trichiurus javaensis sp. nov., and provide a formal morphological description and diagnostic characterization of this species.

4
A new species of Rana from Anhui, China (Anura, Ranidae)

He, Z.; Wang, S.; Wu, S.; Bai, Y.; Wei, J.; Li, Y.; Li, H.; Liu, Y.; Li, X.; Wu, X.; Wang, S.

2026-04-24 zoology 10.64898/2026.04.24.720648 medRxiv
Top 0.1%
2.8%
Show abstract

The diversity of the brown frog genus Rana may be underestimated as the high similarity of morphological characters. A new species belonging to the genus Rana is delineated based on eight specimens obtained from the Tianma National Nature Reserve, Jinzhai County, Luan City, Anhui Province, China. The phylogenetic analysis based on three mitochondrial genes (12S, ND2, and Cyt b) and one nuclear gene (BDNF) showed that the new species formed an independent clade closely related to R. culainensis and received strong support. In addition, morphological differentiation confirmed the phylogenetic results, and both supported the validity of a new species (Rana tianmaensis sp. nov.) in the R. japonica species group. The discovery of this new species enhances peoples understanding of the biodiversity of Rana and can provide important foundational data for scientific decision-making on protected area construction, ecological conservation, and species diversity. With the inclusion of newly described species in this study, the distribution of Rana genus in China now includes 31 recognized species.

5
Five Decades of Rariphotic Research: A Systematic Reviewof Trends, Biases, and Future Directions

Haim, A.; Eyal, G.

2026-07-08 zoology 10.64898/2026.07.07.736978 medRxiv
Top 0.1%
1.5%
Show abstract

The rariphotic zone, typically spanning depths of approximately 130 to 300 meters, represents a key transition between light-dependent coral reef ecosystems and the aphotic deep sea. Despite its potential ecological importance, including its proposed role as a refuge for species exposed to climate-driven stress, rariphotic ecosystems remain poorly understood. In this study, we conducted a systematic review and synthesis of the scientific literature on these habitats from 1970 to 2025. Following the PRISMA 2020 protocol, we analyzed 185 studies to characterize the historical development of research, identify geographic and methodological biases, and assess shifts in research priorities over five decades.Our results show a marked increase in research effort over the last decade, driven in part by advances in underwater technologies such as Remotely Operated Vehicles (ROVs), Human Occupied Vehicles (HOVs), and Baited Remote Underwater Video Station (BRUVS). However, this growth remains uneven, with persistent biases toward benthic rather than pelagic studies and a strong concentration of research in geographically accessible regions. Multivariate analyses of research novelty indicate that technological innovation and the formal recognition of the rariphotic zone in 2018 corresponded with major structural shifts in literature. Although the rariphotic zone is now increasingly recognized as an ecologically distinct component of the reef continuum, it remains underrepresented in ecological theory and conservation frameworks. Future research should move beyond descriptive taxonomic mapping toward integrative, data-driven functional ecology, with particular emphasis on long-term monitoring and depth-stratified connectivity.

6
The invasive soft coral Xenia umbellata has been confirmed in Cuban waters

Schizas, N. V.; Toledo-Rodriguez, D. A.; Jimenez Marrero, N. M.; Weil, E.; Veglia, A. J.; McFadden, C. S.; Munoz-Maravilla, J. D.; Espinosa Saez, J.; Martinez Perez, A.; Estrada, R.; del Carmen Luguera, Y.

2026-06-11 ecology 10.64898/2026.06.08.730793 medRxiv
Top 0.1%
1.5%
Show abstract

Octocoral colonies with unusual morphology were detected in September 2022 and October 2023 in two coastal areas east of Havana, Cuba, and tentatively identified as Unomia stolonifera. U. stolonifera is an invasive octocoral from the Indo-Pacific that was first reported in the Caribbean off Venezuela in the 2000s, where it has spread rapidly, smothering coral reefs and substantially altering benthic communities. After obtaining tissue samples from a Cuban octocoral colony, we re-examined the specimen using molecular barcoding of three mitochondrial regions (16S/ND2, mtMutS, COI) and the nuclear large ribosomal subunit (28S rRNA), and we unequivocally identified it as Xenia umbellata. X. umbellata, a native of the Red Sea, was first identified in southern Puerto Rico in October 2023 and has since been found in various marine ecosystems along the southern coast of the island. The presence of either invasive octocoral species in Cuba or elsewhere in the Caribbean would be of a serious environmental concern due to their documented tolerance, totipotentiality, propagation capacity and significant negative interactions with local benthic fauna. Attempts to eradicate the invasive soft coral colonies from Cuban waters have been initiated with apparent success, helping to control further expansion. The most likely introduction pathway is the accidental or intentional releases from the aquarium trade but transport via ballast water cannot be ruled out. We cannot discount the possibility of independent invasion events from different routes to Puerto Rico and Cuba occurring within a year of each other. Propagation from Cuba to Puerto Rico, or vice versa, which we consider highly improbable, would likely imply that soft coral populations may also have been established on Hispaniola but have remained undetected in the Dominican Republic and Haiti to date.

7
First record of the subfamily Eucerotinae (Hymenoptera: Ichneumonidae) from the mainland Afrotropics, with a description of a new species

Hopkins, T.; Nascimento, A.; Santos, B. F.; Hovorka, T.; Sääksjärvi, I. E.; Österman, E. M.

2026-05-14 zoology 10.64898/2026.05.11.724332 medRxiv
Top 0.1%
1.2%
Show abstract

The ichneumonid subfamily Eucerotinae has been thought to be almost absent from the tropics, with the only known Afrotropical species found in Madagascar. We report the subfamily to be present in the mainland Afrotropics, and describe a new species, Euceros species 1 from Uganda and Cameroon (name not yet shown in preprint). The subfamily had likely not been observed in the mainland Afrotropics before due to low abundances and insufficient sampling. More Eucerotinae likely remain to be discovered in tropical Africa and Asia, although tropical America may genuinely have few eucerotine species. Much more extensive sampling will be needed before it is possible to make confident estimates of how eucerotine diversity is distributed globally.

8
The Brightly Coloured Invaders: A Characterisation of the Invasive Lema Beetle, Lema equestris (Coleoptera: Chrysomelidae), in Hawaii

Weaver, M.

2026-04-30 zoology 10.64898/2026.04.28.721477 medRxiv
Top 0.1%
1.0%
Show abstract

Introduced to Hawaii in 2016, Lema equestris has become a garden pest commonly reported on Solanum americanum, which is grown as a native and cultural plant in Hawaii and supports native vertebrates elsewhere across Oceania. Originally identified as L. solani, the species was later found to have been misidentified. Here, molecular and morphological evidence is used to discriminate Hawaiian specimens from L. solani and support the updated identification of L. equestris. As a new invasive species, it is important to confirm host associations and determine whether it will prey on important species, such as endemic or endangered plants, in its new range or any potential range to which it could spread. To this end, feeding assays were performed with adults, first-instar larvae, and newly hatched naive larvae on 11 potential hosts, comprising mostly Solanum species: Solanum americanum, potato, tomato, tomatillo, poha (gooseberry), chili pepper, eggplant, tobacco, tree tobacco, cabbage, and Brazilian nightshade. While feeding was attempted on cabbage, poha berry, and Brazilian nightshade, no host besides S. americanum supported survival. Rearing was used to further characterize the biology and life history of L. equestris, including instar length and distinctive morphological traits for identifying each life stage. While many basic biological traits are confirmed here, much remains to be studied to better understand this species and why it has begun to spread.

9
Northward expansion of Rugulopteryx okamurae (Dictyotales, Ochrophyta) in the southeastern Iberian Peninsula: first record in Calpe (Comunitat Valenciana)

RODRIGUEZ-GARCIA, E.; FERNANDEZ DEL CAMPO, J.; DOBSON, J. Y.; FONFRIA, E. S.; BORDEHORE, C.; PENA-MARTIN, C.

2026-07-11 ecology 10.64898/2026.07.07.736054 medRxiv
Top 0.1%
0.9%
Show abstract

The non-indigenous brown macroalga Rugulopteryx okamurae has emerged as one of the most aggressive marine invaders in European waters, deeply altering benthic communities and causing severe socioeconomic impacts. While its expansion has been extensively documented along the southern Iberian Peninsula, understanding the dynamics of its northward range expansion along the Spanish Mediterranean coast remains critical for coastal management. This study documents the first formal record of R. okamurae in Calpe (Alicante), representing its current northernmost distribution limit within the Comunitat Valenciana. Sampling was conducted through an initial opportunistic scuba diving observation along the surrounding waters of the Penyal dIfac Natural Park, followed by targeted underwater surveys and an ad hoc inspection of commercial bottom-trawling nets drying at the port of Calpe during June 2026. Morphological and anatomical identification was confirmed through cross-sections of the thallus under optical microscopy, revealing the presence of both the thick and intermediate morphotypes of the species. The collected specimens were found either entangled within a native photophilic algal canopy in shallow waters or recovered from deeper offshore fishing grounds. Given the absence of records in the area during 2023-2025 surveys, these findings suggest either a very recent front-wave colonization event or a contribution from nearby, yet undetected, established patches, driven by secondary local dispersal mechanisms such as drifting fragments and explicitly highlighting commercial fishing activities as an active vector. Furthermore, considering that the species was recorded within a marine protected area and deeper environments, these results highlight a potential ecological threat to local benthic ecosystems, emphasizing the urgent need f or competent authorities to implement spatiotemporal monitoring and public awareness campaigns to prevent the definitive establishment of this invader.

10
Diversity of Mammal Fauna in a Remnant of the Atlantic Forest in the Middle of a Megalopolis

Furtado, M.; Goncalves, A. F.; Fernandes, M. S.; Porfirio, G. E. O.; Camargo, M. M. d.

2026-06-08 zoology 10.64898/2026.06.05.730359 medRxiv
Top 0.1%
0.9%
Show abstract

A remnant Atlantic Forest fragment within Sao Paulos urban environment supports six mammal species, with Didelphis being most abundant, while maintaining natural temporal activity patterns and successful reproduction, demonstrating the conservation value of small protected areas within megacities for preserving native wildlife despite intense anthropic pressure. The Forest Reserve of the Institute of Biosciences (FRIB) is a remnant of the Atlantic Forest located at the University of Sao Paulo, city of Sao Paulo campus, in Brazil. Despite urban pressures such as altered food resources, pollution, pathogens, and interactions with invasive and domestic species, several wildlife species persist, demonstrating adaptability to urban environments. This study aimed to sample the mammal species diversity of FRIB using camera traps. A total of 367 records of six mammal species were obtained over 107 days of sampling, between June and November 2024, resulting in 7,872 hours of sampling effort. The species recorded were Callithrix jacchus, Callithrix penicillata, Didelphis aurita, Didelphis albiventris, and unidentified species of the orders Chiroptera and Rodentia. Didelphis sp. was the most recorded genera with 201 records. These results highlight the significance of this forest fragment in protecting wild animals in an environment facing intense anthropic pressure. ResumoA Reserva Florestal do Instituto de Biociencias (FRIB) e um remanescente da Mata Atlantica situado na Universidade de Sao Paulo, em Sao Paulo, Brasil. Apesar das pressoes urbanas, como mudancas nos recursos alimentares, poluicao, patogenos e interacoes com especies invasoras ou domesticas, diversas especies de animais selvagens continuam existindo, evidenciando sua capacidade de adaptacao aos ambientes urbanos. O objetivo deste estudo foi amostrar a diversidade de especies de mamiferos da FRIB atraves de armadilhas fotograficas. Durante um periodo de 107 dias de amostragem, de junho e novembro de 2024, foram obtidos 367 registros de seis especies diferentes de mamiferos, totalizando 7.872 horas de esforco. As especies registradas foram Callithrix jacchus, Callithrix penicillata, Didelphis aurita, Didelphis albiventris, alem de especies nao identificadas das ordens Chiroptera e Rodentia. Didelphis sp. foi o genero com maior numero de registros (n=201). Esses resultados ressaltam a importancia desse fragmento florestal na protecao da fauna selvagem em um ambiente que enfrenta intensa pressao antropica.

11
Cave-dwelling Planariidae in Croatia exhibit differing levels of cave trait evolution

Kauf, L.; Vila-Farre, M.; Ficze-Schmidt, F.; Bakula, E.; Rink, J.; Bilandzija, H.

2026-05-13 zoology 10.64898/2026.05.09.723976 medRxiv
Top 0.1%
0.8%
Show abstract

The Dinaric karst of Croatia encompasses a network of over 10,000 caves and represents one of the worlds most important subterranean biodiversity hotspots. It is inhabited by remarkably diverse and often endemic species, including planarian flatworms, which are among the rarest macroinvertebrates encountered in cave habitats. Although the presence of cave planarians has long been known, no integrative research on this group has been conducted to date, and the evolutionary relationships between these animals and their surface water counterparts are currently unresolved. To address these gaps, we combined field sampling, phylogenetic analysis based on COI and 18S genes, and phenotypic characterization. Our results show that cave planariids in Croatia belong to at least three genera and are more widespread and diverse across both Croatia, and the broader Dinaric karst, than previously assumed. We increased the number of cave records in the Dinaric karst from 26 to 37 and documented cf. Atrioplanaria and Phagocata in Croatian caves for the first time. Phylogenetic reconstructions suggest numerous independent cave colonization events, including multiple instances within the genera Crenobia and cf. Atrioplanaria. Variation in pigmentation and eye reduction, both within and between populations, further reveal heterogeneous evolutionary trajectories of cave-associated phenotypes. The biogeographical patterns and high genetic diversity we report here point to a complex evolutionary history of planariids in the Dinarides. Our newly generated molecular phylogenies and systematic documentation of trait variability establish Planariidae as a valuable model for studying mechanisms underlying convergent evolution of pigment loss and eye reduction in cave environments.

12
Endangered Species Act listing is linked with greater research effort for U.S. butterflies

Walsh, R. L.; Martin, N. W.; de Bem Oliveira, I.; Daniels, J. C.; Guralnick, R. P.; Kawahara, A. Y.

2026-06-03 zoology 10.64898/2026.05.30.729000 medRxiv
Top 0.1%
0.6%
Show abstract

Conservation strategies for at-risk species can be aided significantly by research on topics such as ecology, life history, and threats, yet research effort is lacking for many species facing elevated extinction risk. Here we investigated whether listing under the U.S. Endangered Species Act (ESA) was associated with research effort for U.S. butterflies, and whether that effort was higher before or after ESA listing. We found that ESA-listed species had significantly more peer-reviewed publications than non-listed species after accounting for species range and taxonomic family. Further, we showed that more papers were published per year after ESA listing than before. These findings confirm that ESA-listed species benefit from greater research attention that can support data-informed conservation efforts. However, the relative scarcity of studies prior to ESA listing, as well as the lack of research for many unlisted, at-risk taxa, underscores the need for proactive, strategic research effort to inform conservation action.

13
A Taxonomic Revision of the Monocaul Phanerophyte Ardisia (Primulaceae) of Gabon

Cheek, M.;Murdoch, H.

2026-06-27 Plant Biology 10.64898/2026.06.26.734757 medRxiv
Top 0.1%
0.5%
Show abstract

Monocaul Ardisia (Primulaceae) have a single, vertical, woody stem and spiral phyllotaxy. They range from 30 cm to 100 cm tall. Three species of this architectural group, Ardisia mayumbensis, A. hallei and A. bracteata, have been recorded from Gabon hitherto. In this taxonomic revision we show that A. mayumbensis does not occur in Gabon, and we describe three new species. Two of these, Ardisia doudou sp. nov.and A. mica sp.nov., are endemic to Gabon and one, A. litterbin sp.nov, is found in both Gabon and Republic of the Congo. Ardisia hallei and A. bracteata are redescribed. All five species have a litter-gathering habit with a terminal funnel of leaves, and two of these species, Ardisia doudou and Ardisia litterbin, also possess adventitious roots in the distal part of the stem, a well-established strategy found in litter-gathering forest species of other plant families in tropical Africa. We provisionally assess the conservation status of all five taxa using the 2012 IUCN standard, finding that all monocaul Ardisia in Gabon fall within threatened categories. Two of the species, Ardisia bracteata and A. mica, are known from single collections and have not been seen for 164 and 63 years respectively and are conceivably extinct although further surveys are needed to establish this. We employ new characters in delineating and describing African Ardisia using leaf thickness and oil gland data.

14
Northward expansion of the barnacle Fistulobalanus albicostatus in Japan

Tamechika, M. M.; Shahdadi, A.; Chan, B. K. K.

2026-07-06 ecology 10.64898/2026.07.06.736396 medRxiv
Top 0.1%
0.5%
Show abstract

Fistulobalanus albicostatus Pilsbry, 1916 (Thoracica: Balanidae) is a tropical to temperate species distributed in the NW Pacific. The previously known northernmost record of this species in Japan was from Aomori Prefecture, at the northern end of Honshu Island, Japan. However, field surveys conducted in 2023 and 2026 confirmed the occurrence of F. albicostatus in Hakodate Bay, the southern end of Hokkaido, Japan, across the Tsugaru Strait, thereby extending the northern limit of its known distribution. A line transect survey conducted in May 2026 recorded seven living individuals within an area of 128 m. F. albicostatus was rare on the mid-high shores, accounting for only 2% of all barnacle individuals in a quadrat survey. The basal diameter of the living individuals ranged from 0.76 to 1.23 cm, and all individuals possessed ovaries. Based on characteristics of both morphological and COI gene, the specimens were identified as F. albicostatus, and belonged to the same haplotype of populations that are present in Honshu Island. The establishment of F. albicostatus in Hokkaido suggests an ongoing northward range shift of this warm-water species, with the potential for further expansion under continued ocean warming.

15
Distribution and diet of Central American Clouded Tiger Cat Leopardus pardinoides oncilla via noninvasive genetics

Rodgers, T. W.; Salom-Perez, R.; Arroyo-Arce, S.; Viquez-Alvarado, E.; Castillo-Caballero, P. L.; Araya-Gamboa, D.; Monteza-Moreno, C. M.; Mooring, M. S.; Vargas, M.; Mock, K. E.

2026-05-29 zoology 10.64898/2026.05.26.727971 medRxiv
Top 0.2%
0.5%
Show abstract

The Clouded Tiger Cat Leopardus pardinoides is a recently recognized Neotropical species for which ecological and natural history data are sparse. Knowledge of species distribution and elevational range are largely based upon camera trap studies, and its diet has not been examined. The objective of this study was to better define the geographical and elevational distribution of the subspecies L. pardinoides oncilla in Central America using genetically confirmed records. We also provide the first diet analysis for L. pardinoides. We conducted extensive surveys for scat samples by visual means and with a scent detection dog across mountain ranges in Panama and Costa Rica, confirmed species identity using Sanger sequencing of mitochondrial DNA, and analyzed diet composition via DNA metabarcoding. Altogether, we collected 195 confirmed L. pardinoides scats. Records were strongly associated with high elevations, with a median elevation of 2805 m, and a maximum of 3422 m. Our findings highlight core habitat for L. pardinoides in the Cordillera Talamanca mountains in the border region of Panama and Costa Rica, and we identified isolated populations from the Central Volcanic Cordillera of Costa Rica and the Central Cordillera of Panama. DNA metabarcoding detected 59 vertebrate taxa. Diet was dominated by small mammals (74% of samples), especially cricetid rodents and shrews. Birds were also commonly detected (35% of samples), while reptiles (13%) and amphibians (1.9%) were less frequent. Estimated median adult prey mass was low (25 g), indicating that the species specializes on small prey. Most vertebrate prey identified were species endemic to montane regions of Panama and Costa Rica. These findings provide valuable ecological and natural history data on Clouded Tiger Cats in Central America that will inform conservation and management of this recently recognized species.

16
Changes in the microbiome of the trophosome of Lamellibrachia satsuma induced by rearing

Koito, T.; Tahara, M.; Taira, R.; Yamaki, A.; Sugimura, M.; Makita, H.; Yamamoto, T.; Yamanaka, T.

2026-05-06 zoology 10.64898/2026.04.29.721791 medRxiv
Top 0.2%
0.5%
Show abstract

BackgroundAdult vestimentiferan tubeworms inhabiting hydrothermal vents and cold seeps lack a mouth and anus and rely entirely on organic matter produced by sulfur -oxidizing autotrophic bacterial symbionts in their trophosomes. These symbionts, which predominantly belong to the genus Proteobacteria, are acquired horizontally from the environment. However, the effects of rearing conditions that differ from natural habitats on the microbiome composition or abundance of these bacteria remain unclear. MethodsWe conducted a metagenomic analysis of Lamellibrachia satsuma reared in an aquarium under sulfide-supplemented and sulfide-free conditions. ResultsImmediately after collection, the microbiome was dominated by known symbionts within {gamma}-Proteobacteria, exhibiting low species diversity. After 6 months of rearing, the abundance of these symbionts significantly decreased under both conditions, whereas overall bacterial diversity increased. In particular, -Proteobacteria became more abundant under sulfide-supplemented conditions, while {delta}-Proteobacteria predominated in the absence of sulfide. Despite these changes, symbionts were not entirely lost, and the hosts survived for 6 months, likely due to their low metabolic rate. These findings suggest that the microbiome of L. satsuma can respond flexibly to changes in the rearing environment. They also indicate that the hosts metabolism can be maintained even with a smaller quantity of symbiotic bacteria.

17
Labyrinthula merlionensis sp. nov.: a novel labyrinthulid infecting marine diatoms

Sim, C. W. H.; Walde, M.; Strindberg, H.; Kaur, A.; le Panse, S.; Gourvil, P.; Jahren, J.; Vaulot, D.; Lopes dos Santos, A.

2026-04-29 ecology 10.64898/2026.04.28.721384 medRxiv
Top 0.2%
0.5%
Show abstract

Labyrinthulomycetes are a class of fungus-like heterotrophic protists from the Stramenopiles lineage, recognized for their ecological role as decomposers and contributors to nutrient cycling. They colonize various substrates, from seaweed to terrestrial environments, utilizing ectoplasmic networks for nutrient absorption. This study characterized a novel Labyrinthula strain associated with the marine diatom Biddulphia. Phylogenetic analysis of the full-length 18S rRNA gene positioned this strain as a new species, Labyrinthula merlionensis sp. nov. Scanning electron and light microscopy observations revealed bi-flagellated zoospores and spindle-shaped vegetative cells with ectoplasmic networks. Time-series observations of the interactions between L. merlionensis and Biddulphia were categorised into different phases: establishment, infection, and aggregation. Scanning electron and confocal microscopy observations during the infection phase established the use of ectoplasmic nets to target the marginal ridge regions between diatoms, and the detection of labyrinthulid cells within diatom frustules. These findings enhance the understanding of the diversity, morphology, and ecological roles of Labyrinthulomycetes, particularly their intra- and extra-cellular interactions with diatom hosts.

18
Two new threatened Inversodicraea (Podostemaceae) species from Sierra Leone: I. joulei and I. lebbiei

Massally, F. K.; Lebbie, A.; van der Burgt, X.; Plummer, J.; Cheek, M.

2026-05-20 plant biology 10.64898/2026.05.18.725858 medRxiv
Top 0.2%
0.4%
Show abstract

Two threatened new species of Podostemaceae belonging to the genus Inversodicraea, I. joulei and I. lebbiei, both from the Republic of Sierra Leone, are described and illustrated. A first record in Sierra Leone of the genus Lestestuella is also reported. Inversodicraea is the most species-rich genus of Podostemaceae in Africa and now comprises 38 species. Inversodicraea joulei is easily recognised because it has a persistent spine distally on the median rib of each fruit valve, and scattered, membranous scale-leaves with broadly rounded apices, while Inversodicraea lebbiei is distinct in having narrowly triangular robust scale-leaves which are inrolled, spreading distally, and completely covering the stem, arranged in five ranks. Inversodicraea joulei is known from a single location with three sites while I. lebbiei is known from two locations each with one site. Using the latest IUCN Red List guidance, Inversodicraea joulei is assessed as Critically Endangered and I. lebbiei is assessed as Endangered, due to threats from dam construction projects, agricultural practices and mining activities, resulting in high levels of siltation on rocks in the fast-flowing rivers where these species grow.

19
First hematological and biochemical data in a rehabilitated giant pangolin (Smutsia gigantea) from southern Cameroon

Montblanc, M.; Harvey-Carroll, J.; Vanassche, J.; Donaldson, M.; Connelly, E.; Hywood, L.

2026-05-03 zoology 10.64898/2026.04.29.721582 medRxiv
Top 0.2%
0.3%
Show abstract

Giant pangolin (Smutsia gigantea) is one of the least studied pangolin species worldwide, with no published hematological and biochemical data available. We report the first blood parameters from a rehabilitated adult male from Campo Maan National Park (southern Cameroon). Hematological and biochemical findings are described and discussed in relation to available data from other pangolin species. These preliminary results provide the first reference framework for this species and highlight their relevance for clinical assessment, health monitoring, and conservation management.

20
The mitochondrial genome of the hammerhead flatworm Bipalium nobile and its phylogenetic implications

Omura, M.; Tomihara, S.; Minei, R.; Haraguchi, D.; Wada, S.

2026-06-02 zoology 10.64898/2026.05.31.729009 medRxiv
Top 0.2%
0.3%
Show abstract

We sequenced the nearly complete mitochondrial genome of the hammerhead flatworm Bipalium nobile Kawakatsu and Makino, 1982 using short-read sequencing technology, yielding a 16,018 bp genome comprising 12 protein-coding genes, 22 tRNA genes, and 2 rRNA genes. The composition and order of genes were consistent with those observed in the closely related species Bipalium kewense and Diversibipalium multilineatum, except for the position of tRNA-Glu. Phylogenetic analysis based on all mitochondrial proteins from species within the family Geoplanidae supports the monophyly of a clade comprising B. nobile, B. kewense, and D. multilineatum. The mitochondrial genome sequence obtained in this study provides a valuable resource for investigating the genetic diversity and population structure of B. nobile, a soil-dwelling predator with the potential for global spread as an invasive organism.