Echinoderes semprucciae: A new species of Kinorhynch from a macerating Neptune Grass environment in the eastern Mediterranean.

Kinorhynchs are tiny (generally less than 1 mm) worm like Animals largely found in marine sediments, for which reason they are sometimes known as 'Mud Dragons'. They appear to be ubiquitous members of the interstitial meiofauna (Animals that live between sediment grains) in shallow marine habitats, but have been studied in relatively few locations. However, not all Kinorhynchs are sediment-dwellers, with members of the group having been found living on a wide range of Algae, marine Plants, and Animals.

In a paper published in The Eutopean Zoological Journal on 3 February 2024, Adele Cocozza di Montanara of the Department of Science and Technology at the Parthenope University of Naples, Alberto González-Casurrubios of the Department of Biodiversity, Ecology and Evolution at the Complutense University of Madrid, and Diego Cepeda of the Centre for Research on Biodiversity and Global Change at the Autonomous University of Madrid, and the Department of Life Sciences at Alcalá University, describe a new species of Kinorhynch from a macerating Neptune Grass environment off the coast of Ischia Island in the western Mediterranean Sea.

Neptune Grass, Posidonia oceanica, is a form of Seagrass endemic to the Mediterranean, where it forms vast meadows in the photic parts of the sea (i.e. those areas where sufficient sunlight penetrates to allow photosynthesis). Seagrasses are important habitat-forming organisms, and a wide range of Animals, including Kinorhynchs are adapted to life in these meadows. However, as well as meadows, Seagrasses also form areas called 'macerating Seagrass detrital bottoms', where large volumes of decomposing leaves and rhizomes accumulate, typically below the photic zone, forming an important marine carbon sink. Whilst these environments have been known since the 1950s, very little attention has been paid to them or the fauna which live there, to which end Cocozza di Montanara et al. have begun a project to study the fauna of the macerating Seagrass detrital bottom environment of the Regno di Nettuno Marine Protected Area, along the coast of Ischia Island off the western coast of Italy.

Study area at 65–80 m depth along the northwestern area of Ischia Island (western Mediterranean Sea). Cocozza di Montanara et al. (2025).

The new species is placed in the genus Echinoderes, and given the specific name semprucciae, in honour of Federica Semprucci of the University of Urbino Carlo Bo, for acting as co-supervisor for Adele Cocozza di Montanara's PhD and supporting and guiding her research on meiofauna. The species is described from two specimens, both collected on 19 June 2020 near Ischia Island, an adult female, collected at a depth of 80 m, and an adult male collected at a depth of 70 m.

Line art illustrations of Echinoderes semprucciae. (a) Ventral view of a female based on holotype (NHMD-1177723). (b) Dorsal view of a female based on holotype (NHMD-1177723). (c) Dorsal view of segments 10–11 of a male based on paratype (NHMD-1177722). Abbreviations: ac, acicular spine; gcoI, type 1 glandular cell outlet; LA, lateral accessory; LD, laterodorsal; ltas, lateral terminal accessory spine; lts, lateral terminal spine; LV, lateroventral; MD, middorsal; ML. midlateral; ne, nephridiopore; pa. papilla; PD. paradorsal; ps, penile spines; SD, subdorsal; ss, sensory spot; t, tube; Vl, ventrolateral; VM, ventromedial; number in abbreviations indicates the corresponding segment. Cocozza di Montanara et al. (2025).

The two known specimens of Echinoderes semprucciae are 202 μm (female) and 193 μm (male) in length, with a retractable mouth cone surrounded by oral styles. This retractable mouth is mounted on an organ called the introvert, which has six concentric rings of scalids and 10 longitudinal sectors defined by the arrangement of primary spinoscalids. Behind the head is a neck section, then a trunk comprising eleven segments, with spines on segments four, six, eight, nine, and eleven; the two spines on segment eleven being elongated to form a pair of tail-like structures.

Light micrographs of female holotype (NHMD-1177723) (a)-(d), (g) and male paratype (NHMD-1177722) (e), (f) of Echinoderes semprucciae. (a) Ventral overview. (b) Head, dorsal view. (c) Head, ventral view. (d) Ventral view of segments 5–6. (e) Lateral view of segments 5–8. (f) Detail of penile spines. (g) Ventral view of segment 11. ltas, lateral terminal accessory spine; lts, lateral terminal spine; lvs, lateroventral spine; lvt, lateroventral tube; pa, papillae; ps, penile spines; te, tergal extension, number after abbreviation indicates the corresponding segment, sensory spots are marked with dashed circles and type 1 glandular cell outlets with closed circle. Cocozza di Montanara et al. (2025).

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Seven new species of Marine Fungi from the Mediterranean.

Marine Fungi are an important and active component of the microbial communities that inhabit the oceans. Fungi in the marine environment live as mutualists, parasites, pathogens and saprobes, and are pivotal to marine food webs because of the recycling of tough organic materials that other organisms cannot break down; besides which, these widely dispersed organisms are a source of novel bioactive compounds. Marine Fungi have been recovered worldwide from a broad range of biotic and abiotic substrata, such as driftwood algae, sponges, corals, sediments, etc. A 'Marine Fungus' is defined as any fungus retrieved repeatedly from marine environment and that reproduces in the marine environment. There are currently about 1680 described Marina Fungal species belonging to 693 genera, 223 families, 87 orders, 21 classes and six phyla. However, considering that the total number of Marine Fungi has been estimated to exceed 10 000 taxa, fungal diversity remains largely undescribed. With more than 900 species, the Ascomycota are the dominant Fungal phylum in the sea.

In a paper published in the journal Diversity on 6 April 2020, Anna Poli, Elena Bovio, Lucrezia Ranieri, Giovanna Cristina Varese, and and Valeria Prigione of the Department of Life Sciences and Systems Biology at the University of Torino describe seven ew species of Marine Ascomycote Fungi from the Mediterranean.

The first new species is placed in a new genus, Parathyridariella, which means 'beside Thyridariella', in reference to a previously described species, to which the new genus is closely related, and given the specific name dematiacea, meaning darkly pigmented, in reference to the colour of the colony on culture media  This species was isolated from a Green Seaweed, Flabellia petiolata, found growing at a depth of 14-15 m off the coast of Ghiaie Beach on the island of Elba, and a Seagrass, Posidonia oceanica, growing at a depth of 5-21 m off the coast of Punta Manara in the Province of Genoa, Italy. Colonies of this Fungus grown on Malt Extract Agar-sea water media reached 28–34 mm in diameter after 28 days at 24 °C, grown on Oatmeal Agar-sea water reached 40-34 mm in diameter after 28 days at 24°C, and on Potato Dextrose Agar-sea water reached 36-49 mm in diameter after 28 days at 24 °C, and 15.5–22.5 mm in diameter after 28 days at 15°C. The species grew actively on Pine wood and cork. The mycelium varies in colour from dark grey/black to dark green, and is dense with radial grooves and concentric rings, and submerged edges; the reverse is dark green. A brown exudate present above the concentric rings. The hyphae are 2.8–4.8 m wide, septate, hyaline to lightly pigmented. Parathyridariella dematiacea produces numerous Chlamydospores (thick-walled hyphal cells which function like spores), but neither sexual morphs or asexual conidiogenesis (spore production) were seen.

Parathyridariella dematiacea, 28-days-old colony at 21°C on Malt Extract Agar-sea water media (A) and reverse (B); solitary (C) and in chain (D) chlamydospores. Scale bars are 10 μ m (C), (D). Poli et al. (2020).

The second new species is also placed in the genus Parathyridariella, and given the specific name tyrrhenica, in reference to the Tyrrhenian Sea, where it was discovered. This species was isolated from a Brown Seaweed, Padina pavonica, (Peacock's Tail), and a Green Seaweed, Flabellia petiolata, both found growing at a depth of 14-15 m off the coast of Ghiaie Beach on the island of Elba. Colonies of this Fungus grown on Malt Extract Agar-sea water media reached 10 mm in diameter after 28 days, at 21° C, grown on Oatmeal Agar-sea water reached 48-50 mm in diameter after 28 days at 24°C, and 26-29 mm in diameter after 28 days at 15°C, and on Potato Dextrose Agar-sea water reached 31–46 mm in diameter after 28 days at 24 °C, and 16–19 mm in diameter after 28 days at 15°C. The species grew actively on Pine wood and cork. The mycelium is funiculose (made up of rope-like strands), yellowish, land ightly ochre at the edges; the reverse is light yellow, lighter at the edges. The hyphae are 5 μm diameter, septate, hyaline to brownish, sometimes wavy or swollen, forming hyphal strands. No reproductive structures were observed.

Parathyridaria tyrrhenica, 28-days-old colony at 21°C on Malt Extract Agar-sea water media (A) and reverse (B); mycelium (C), black and white arrows indicate hyphal strands and wavy hyphae, respectively. Scale bar is 10 μ m. Poli et al. (2020).

The third species described is also placed in the genus Parathyridaria, and given the specific name flabelliae, in reference to the Green Seaweed, Flabellia petiolata, on which it was found growing, at a depth of 14-15 m off the coast of Ghiaie Beach on the island of Elba. Colonies of this Fungus grown on Malt Extract Agar-sea water media reached 37–44 mm in diameter after 28 days, at 21° C, grown on Oatmeal Agar-sea water reached 60 mm in diameter after 28 days at 24°C, and 33–35 mm in diameter after 28 days at 15°C, and on Potato Dextrose Agar-sea water reached 53–64 mm in diameter after 28 days at 24 °C, and 23–24 mm in diameter after 28 days at 15°C. The species grew actively on Pine wood and cork. The mycelium is funiculose (made up of rope-like strands), and whitish with submerged edges; the reverse is brown in the middle, lighter at edges. The hyphae are 2.6-5 μ m wide, septate and hyaline. Parathyridariella flabelliae produces numerous Chlamydospores, which are globose or subglobose, from light to dark brown in colour, and either unicellular (4 x 5 μ m diameter) or multicellular (up to four-celled and 8 x 12 μm diameter), but neither sexual morphs or asexual conidiogenesis (spore production) were seen.

Parathyridaria flabelliae, 28-days-old colony at 21°C on Malt Extract Agar-sea water media (A) and reverse (B); unicellular and multicellular chlamydospores (C). Scale bar is 10 μm. Poli et al. (2020).

The fourth  new species described is placed in the genus Neoroussoella, and given the specific name lignicola, which implies it grows on dead wood.  This species was isolated from a Brown Seaweed, Padina pavonica, (Peacock's Tail), and a Seagrass, Posidonia oceanica, both found growing at a depth of 14-15 m off the coast of Ghiaie Beach on the island of Elba. Colonies of this Fungus grown on Malt Extract Agar-sea water media reached 28–29 mm in diameter after 28 days, at 21° C, grown on Oatmeal Agar-sea water reached 27-40 mm in diameter after 28 days at 24°C, and 14.5-26 mm in diameter after 28 days at 15°C, and on Potato Dextrose Agar-sea water reached 38–45 mm in diameter after 28 days at 24 °C, and 19–29 mm in diameter after 28 days at 15°C. This species grew efficiently on Pine wood. The mycelium is grey to dark green and floculose, with irregular edges, the reverse is dark grey. A clear exudate is often present. Hyphae are 2–4.4 m wide, septate, hyaline, and assume a toruloid aspect when growing into wood vessels; they form chains of two-celled chlamydospores which, at maturity, protrude from the vessels. The chlamydospores are 7.4 x 5.2 μ m, from light to dark brown, and globose or subglobose. Neither sexual morphs or asexual conidiogenesis (spore production) was seen.

Neoroussoella lignicola, 28-days-old colony at 21°C on Malt Extract Agar-sea water media (A) and reverse (B); two-celled chlamydospores inside wood vessels (C). Scale bar is 10 μm. Poli et al. (2020).

The fifth new species described is placed in the genus Roussoella, and given the specific namemargidorensis, meaning 'from Margidore'; the species was isolated from  a Brown Seaweed, Padina pavonica, (Peacock's Tail), found growing at a depth of 14-15 m off the coast of Margidore on the island of Elba. Colonies of this Fungus grown on Malt Extract Agar-sea water media reached 33-34 mm in diameter after 28 days, at 21° C, grown on Oatmeal Agar-sea water reached 45 mm in diameter after 28 days at 24°C, and 27 mm in diameter after 28 days at 15°C, and on Potato Dextrose Agar-sea water reached 45 mm in diameter after 28 days at 24 °C, and 23 mm in diameter after 28 days at 15°C. This species grew actively on Pine wood. The mycelium is whitish, lighter to the edge, and umbonate (having a rounded knob or protuberance) in the middle, the reverse is ochre. Hyphae are approximately 2 μm wide, septate and brownish. Neither sexual morphs or asexual conidiogenesis (spore production) was seen.

Roussoella margidorensis, 28-days-old colony at 21°C on Malt Extract Agar-sea water media (A) and reverse (B); chlamydospores (C). Scale bar is 10 μ m. Poli et al. (2020).

The sixth new species described is also placed in the genus Roussoella, and given the specific name mediterranea, in reference to the Mediterranean Sea. The species was isolated from  a Brown Seaweed, Padina pavonica, (Peacock's Tail), found growing at a depth of 14-15 m off the coast of Margidore on the island of Elba. Colonies of this Fungus grown on Malt Extract Agar-sea water media reached 55 mm in diameter after 28 days, at 21° C, grown on Oatmeal Agar-sea water reached 67–72 mm in diameter after 28 days at 24°C, and 33–38 mm in diameter after 28 days at 15°C, and on Potato Dextrose Agar-sea water reached 69–76 mm in diameter after 28 days at 24 °C, and 32.5–39 mm in diameter after 28 days at 15°C. This species grew actively on Pine wood, and poorly on cork. The mycelium is light grey, and floccose, with an umbonate area in the middle, the reverse is brown with lighter edges. A dark exudate present. Hyphae are 2.4 μm wide, septate and dematiaceous. Branched chains of light to dark brown chlamydospores often present, these are 4.5 x 5.7 μm, and from unicellular to 4-celled. Neither sexual morphs or asexual conidiogenesis (spore production) was seen.

Roussoella mediterranea, 28-days-old colony at 21°C on Malt Extract Agar-sea water media (A) and reverse (B); unicellular and multicellular chlamydosporesn indicated by a black arrow (C). Scale bar is 10 μ m. Poli et al. (2020).

The final species is also placed in the genus Roussoella, and given the specific name padinae, in reference to the Brown Seaweed, Padina pavonica, (Peacock's Tail), upon which it was found growing, at a depth of 14-15 m off the coast of Margidore on the island of Elba. Colonies of this Fungus grown on Malt Extract Agar-sea water media reached 53 mm in diameter after 28 days, at 21° C, grown on Oatmeal Agar-sea water reached 57.5–65 mm in diameter after 28 days at 24°C, and 30–35 mm in diameter after 28 days at 15°C, and on Potato Dextrose Agar-sea water reached 60–69 mm in diameter after 28 days at 24 °C, and 30–34 mm in diameter after 28 days at 15°C. This species grew poorly on Pine wood, and efficiantly on cork. The mycelium is from grey to dark green, floccose in the middle, with radial grooves, and fimbriate edges; the reverse is brown. Hyphae are 3 μm wide, septate, brownish and assume a toluroid aspect when growing into wood vessels, and form chains of two-celled chlamydospores which, at maturity, protrude from the vessels. These chlamydospores are 5–7 x 4 μm, from light to dark brown in colour, subglobose, ellipsoidal or cylindrical. Neither sexual morphs or asexual conidiogenesis (spore production) was seen.

 Roussoella padinae, 28-days-old colony at 21°C on Malt Extract Agar-sea water media (A) and reverse (B); toruloid hyphae (C) and two-celled chlamydospores (D) inside wood vessels. Scale bars are 10 μm. Poli et al. (2020).

The description of these new taxa was particularly challenging because neither asexual nor sexual reproductive structures developed in axenic conditions. Therefore, Poli et al. were unable to describe the range of anatomical variations and diagnostic features among these newly recognized phylogenetic lineages. Indeed, strictly vegetative growth without sporulation is a common feature of many marine Fungal strains. Possibly, these organisms rely on hyphal fragmentation for their dispersal, or alternatively, the di erentiation of reproductive structures may be obligatorily dependent on the peculiar environmental conditions under which they live (e.g., wet-dry cycles, high salinity, low temperature, high pressure, etc.). During the study of these fungi, Poli et al. tried to mimic the saline environment by using di erent culture media supplemented with natural sea water or sea salts. Although these culture methods were applied to induce sporulation, they observed that only media supplemented with sea water supported a measurable growth of vegetative mycelium. A method tried previously with other Marine Fungi, to induce sporulation by placing wood and cork specimens on the colony surface with their subsequent transfer into sea water, was only partially successful: out of seven species, three (Parathyridariella dematiacea, Parathyridariella flabelliae, Roussoella mediterranea) developed chlamydospores in the mycelium above the wood surface, two (Neoroussoella lignicola, Roussoella padinae) gave rise to resting spores inside wood vessels. Most of the strains preferred to colonise wood rather than cork. These structures were interpreted as 'chlamydospores' instead of 'conidia' for the following reasons: (i) They were characterized by a very thick cell wall, a typical feature of resting spores; (ii) conidiogenous cells were never observed. Additional e orts to force the development of reproductive structures by using Syntetic Nutrient Agar-sea water and Pine needles, were also unsuccessful.

Both Roussoella padinae and Neoroussoella lignicola displayed a similar lignicolous behavior, growing and producing chlamydospores inside wooden vessels, although of di erent size and shape. The ability to form hyphae and to grow inside the wood vessels has been reported for a number of dark septate endophyte Fungi in terrestrial environments, and, recently, for Posidoniomyces atricolor, marine endophyte that lives in association with the roots of the Seagrass, Posidonia oceanica. By definition, endophytes live inside living plant tissues. To induce sporulation, sterilized specimens of dead wood were employed, therefore Roussoella padinae and Neoroussoella lignicola were inferred to be 'lignicolous Fungi' rather than 'endophytes'. The observation of this growth characteristic in two di erent genera, may find its reason in an evolutionary adaptation to marine life in association with lignocellulosic matrices. Therefore, Poli et al. hypothesise their ecological role as saprobes involved in degrading organic matter.

Most of the Roussoellaceae (the family that includes the genera Roussoella and Neoroussoella) and Thyridariaceae (the family that includes the genus Parathyridariella) described to date are associated with terrestrial plants, especially Bamboo and Palm species. In fact, only two species, Roussoella mangrovei and Roussoella nitidula have previously been retrieved from the marine environment. However, Poli et al. infer that these families may be well represented in the sea, thus improving our knowledge on the largely unexplored Fungal marine biodiversity.

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