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Field campaigns were carried out in the North, Center, and South of Tunisia (2017–2022). Through this, three anophthalmous species of Trichorhina from three different localities in the North and Center-East of Tunisia were recognized as new to science, and consequently as the first record of the genus from Tunisia. A detailed morphological description of these three new species is provided. The abiotic factors of their habitat and micro-habitat are provided as well as their associated fauna. [ABSTRACT FROM AUTHOR]

In July–August 2022, the spatial distribution and the composition of local settlements of the bivalve mollusc Mya japonica Jay, 1857 in the Vostok Bay (Peter the Great Bay of the Sea of Japan) were studied. M. japonica occurred almost throughout the entire bay in a wide range of depths from 0 to 22 m at water temperatures from –1.9 to 25°С and salinity from 0 to 34‰. M. japonica was the most abundant in the shallow areas of the bays, closed from the direct wave impact, where, at a depth of up to 4–5 m, the density of the mollusc reached 27 ind./m2, and the biomass was almost 4 kg/m2, which averaged 56% of the total macrozoobenthos biomass. With increasing depth and moving from the dead-end of the bay to the open sea, the abundance of M. japonica decreased by one or two orders of magnitude. Local settlements differed significantly in size and age composition, size-frequency distribution of molluscs, indicating the nature of the replenishment of the benthic population with juveniles, as well as the proportion of commercial size individuals, which ranged from 37 to 98%. The reasons for the revealed features of the distribution and structure of the population of M. japonica are discussed. [ABSTRACT FROM AUTHOR]

The sub-fossil red coral deposits of Sciacca (Sicily Channel) have attracted scientific attention for nearly 150 years. Their origin and formation have been long questioned and investigated, given the fact that they represent one of the most intriguing geobiological events ever to occur in the Mediterranean basin. Less attention was given to the paleo-community associated with the sub-fossil coral. Radiocarbon age determinations, in particular, were provided only for red coral, neglecting the possibility of understanding which species were simultaneously present in the coralline paleo-community and which was their role. The study of cemented coral rubble pieces revealed that Corallium rubrum covered the largest time interval (more than 3000 years) and was contemporary to many secondary epibionts over two millennia and to Madrepora oculata for about 500 years; this last finding suggested that an uncommon co-dominance between the two structuring species occurred in the nearby living communities. The lack of Fe–Mg deposits on the cemented coral rubbles coupled with the low bioerosion rate of the red coral skeletons by the demosponge Siphonodictyon coralliirubri (assessed through the analysis of the erosive paleo-scars) suggested that the deposits met with a rapid sediment cover-up. Moreover, for the first time, the analysis of a piece of cemented coral rubble of sub-fossil red coral coming from Sardinian waters confirmed that, albeit to a lesser extent, the conditions favouring the preservation of dead corals can occur also in different localities far from Sciacca. [ABSTRACT FROM AUTHOR]

Macrofauna associated with the bamboo coral Isidella elongata was analysed in the Balearic Basin at depths of 697–1308 m. The diversity of associated macrofauna and the specific associations identified depended on different morphological characteristics of colonies, such as height or density of rami. Species associated with Isidella consisted mainly of sessile fauna, such as cnidarians (the actinian Amphianthus dornhii and the solitary coral Desmophyllum dianthus) and cirripeds (Gibossaverruca sp.). The strongest relationship (commensalism) occurred for the Pontogeneiidae amphipod Dautzenbergia megacheir, living attached to colonies of Isidella and represented by all population stages from adult (oostegal) females and males to juveniles. Species-coral relationships between Dautzenbergia and bamboo corals (Isididae) are plausible. Dautzenbergia spp. showed morphological differences between Atlantic (described by Walker 1897 as "eyes wanting") and Mediterranean (with well-developed reddish eyes) specimens. This would suggest diversification of this genus, as has been recently suggested for Pleustidae associated with deep gorgonians. The diversity of the macrofaunal community associated with I. elongata was higher in the most mature (larger colonies with higher density) fields found NW of Mallorca, with higher colonies than in other parts of the Mediterranean. This was the only site where Gibossaverruca sp. (a first Mediterranean faunal record) and D. dianthus were collected. These complex associations between macrofauna and deep-water corals may provide arguments to protect these fragile ecosystems as a source of faunal diversity and diversification. [ABSTRACT FROM AUTHOR]

The vertical distribution of the bivalve Tetrarca boucardi is studied at several sites in Vostok Bay, which largely characterize the diversity of biotopes of the upper subtidal zone of Peter the Great Bay (the Sea of Japan). In this part of the species range, at a depth of 0.5–10 m, T. boucardi forms stable perennial populations, in which there is the regular replenishment by juveniles; the population lifetime apparently many times exceeds the bivalve's individual lifespan. The maximum shell length of T. boucardi is 74 mm; the maximum individual age is 19 years. The most abundant accumulations of T. boucardi with a biomass of 530 g/m2 (36.7% of the total biomass of macrozoobenthos) are found in shallow water at a depth of about 3 m in semi-protected inner parts of the bay, which are well warmed in summer. For the first time, it is found that relatively sheltered habitats on wave-exposed rock reefs mainly at a depth of 0.5–1.5 m are also favorable for the species (average biomass, 72.7 g/m2; 11.2%). T. boucardi also occurred on soft bottoms at a depth of 1–10 m (average biomass, 22.2 g/m2; about 2%) in druses of large bivalves Modiolus kurilensis and Crenomytilus grayanus. Local differences in the abundance and composition of T. boucardi populations are discussed in relation to the habitat conditions. [ABSTRACT FROM AUTHOR]

Bromeliads are widely recognized for their role as biodiversity amplifiers in the Neotropical region. Some animal taxa are well known for their relationships with bromeliads, such as aquatic insects and amphibians, but others, such as lizards, are still neglected when it comes to association with these plants. In this study, we present a bibliographic review about the association of lizards with bromeliads, aiming to determine the diversity of lizard taxa and the geographical distribution of the available records. We found a total of 72 bibliographic sources that reported at least one lizard species in association with bromeliads. These records are distributed in 11 families, 26 genera and 69 lizard species. The geographic distribution of records covers 16 countries and oceanic islands in the Americas, with most records in Brazil. Twenty lizard species are officially threatened to extinction according to IUCN criteria, which corresponds to 29% of all recorded species. Based on these results, we propose actions for the conservation of bromeliads, with consequent conservation of associated lizard species, as has been proposed for amphibians. [ABSTRACT FROM AUTHOR]

The Caribbean scleractinian reef coral Agaricia undata (Agariciidae) is recorded for the first time as a host of the coral-gall crab Opecarcinus hypostegus (Cryptochiridae). The identity of the crab was confirmed with the help of DNA barcoding. The association has been documented with photographs taken in situ at 25 m depth and in the laboratory. The predominantly mesophotic depth range of the host species suggests this association to be present also at greater depths. With this record, all seven Agaricia species are now listed as gall-crab hosts, together with the agariciid Helioseris cucullata. Within the phylogeny of Agariciidae, Helioseris is not closely related to Agaricia. Therefore, the association between Caribbean agariciids and their gall-crab symbionts may either have originated early in their shared evolutionary history or later as a result of host range expansion. New information on coral-associated fauna, such as what is presented here, leads to a better insight on the diversity, evolution, and ecology of coral reef biota, particularly in the Caribbean, where cryptochirids have rarely been studied. [ABSTRACT FROM AUTHOR]

Seaweeds play a key role in the rocky-shore fauna by providing shelter and food for many invertebrate species, which in turn compose the diet of benthic and pelagic predators. This study investigated the effect of the macroalgal host species on an assemblage of associated amphipods, and tested if the host mediates the vulnerability of amphipods to predation. The association of amphipods with the macroalgal hosts Dichotomaria marginata, Padina gymnospora, and Sargassum filipendula was evaluated seasonally for 1 year on a subtropical rocky shore on the southeastern coast of Brazil. The density of amphipods did not vary with season or host. However, the composition of amphipod species was sensitive to the host macroalgal species and varied temporally. A field experiment showed no clear effect of predation on the amphipod assemblage. Also, predation did not explain the spatial or temporal variation of the amphipod assemblage. Our results indicate that the identity of the macroalgal host drove the composition of the associated amphipods, while predation may have a minor role. Therefore, the loss of habitat-forming organisms such as seaweeds is expected to have drastic consequences for the composition of associated fauna, and consequently on the flow of matter and energy in coastal ecosystems. [ABSTRACT FROM AUTHOR]

A study of epibiosis of the brown alga Costaria costata in the sublittoral zone of Vostok Bay, Sea of Japan during the spring and summer of 2016 showed that hermit crabs of the following four species accounted for approximately 85% of the total biomass: Pagurus proximus, P. minutus, P. brachiomastus, and P. middendorffii. Of these, the most abundant one (96.5% of the total number of hermit crabs) was P. proximus, the mean aggregation density of which on C. costata (429 _ 221 ind./m²) was higher by an order of magnitude than that in the adjacent area of the bouldery bottom. The size ranges of males and females of this species in aggregations on boulders and those on C. costata were similar, with a predominance of larger individuals on algae. In the size-frequency distribution, three groups of individuals corresponding to three size-age cohorts were differentiated. The male-to-female ratio was 1 : 1.7. Hermit crab aggregations on C. costata are ephemeral; their existence is determined by the duration of the period of algae development, that is, from late spring to the middle of the summer. [ABSTRACT FROM AUTHOR]

In order to demonstrate how scleractinian corals contribute to marine biodiversity by their host function, information on associated fauna was gathered during a biological survey at St. Eustatius, eastern Caribbean. This knowledge is especially urgent for a host coral such as Helioseris cucullata (Agariciidae), which has undergone strong declines in abundance at various Caribbean localities and has a poor record of associated fauna. New records of H. cucullata as host are presented for the coral gall crab Opecarcinus hypostegus (Cryptochiridae), the Christmas tree worm Spirobranchus giganteus (Serpulidae) and an unidentified serpulid tube worm of the genus Vermiliopsis. A second association record is reported for the coral barnacle Megatrema madreporarum (Pyrgomatidae). Coral-associated copepods were not found on H. cucullata despite a search for these animals. The new records were compared with previous records of other host coral species that showed elements of the same associated fauna. The present findings indicate that new discoveries concerning Caribbean coral reef biodiversity can still be made during field expeditions by targeting the assemblages of associated fauna of specific benthic host species. [ABSTRACT FROM AUTHOR]

The first living sample of Lophelia pertusa from Greenlandic waters was inadvertently collected at 60.3675°, −48.45528°, entangled together with other corals to a seawater sampler and property sensor (CTD) package. We collected in situ photographs taken at two sites in the same area in order to determine whether a reef was present. We identified reef-like structures formed by living and dead L. pertusa at 886-932 m depth on a steep slope. We assembled and analyzed hydrographic data to characterize the reef environment in order to facilitate future localization of other reefs and predictions of the impacts of climate change. We showed that the reef was located in a layer of modified Atlantic Water of relatively stable bottom temperature (4.1-5.0 °C) and salinity (34.90-34.98) with density slightly higher (27.62-27.71 kg m) than that reported for the occurrence of reefs in the northeast Atlantic, and in an area with exceptionally and persistently high currents of >15 cm s at 1000 m. The intermediate-depth salinity maximum was found in the depth range where the corals were found. We discovered signals of consistent vertical and horizontal transports at 700-900 m over the reef area. Although this area is not directly influenced by intermediate and deep convection in the Labrador Sea, the seasonal evolution of near-bottom temperature, salinity and density for the 700-900 m depth range revealed strong seasonal patterns with both temperature and salinity reducing to their annual minimal values at the end of March and staying low for 1 month with an indication of a second minimum in June, 3 months later. The occurrence and temporal extent of these minima likely arose through a combination of local convection from the surface and advection of cooled and freshened waters at depth from the Irminger Sea. A diversified associated fauna was described; the short list of species compiled from our limited sample comprised species common in the area, as well as rare species, species new to Greenland, and species new to science. [ABSTRACT FROM AUTHOR]

Free-living marine Platyhelminthes of the order Polycladida are known to interact with molluscs, especially bivalves. The impact and damage of polyclads that feed on farmed oysters can be so significant that they are known as oyster leeches. The present contribution identifies three species of polyclads associated with scallop aquaculture at Ilha Grande, southeastern Brazil: one cotylean, Lurymare matarazzoi, and two acotyleans, Imogine tica and Imogine refertus. This is the first time these species are illustrated with photographs of live specimens and histological sections after their original description. This is also the first record of an association of polyclads with a pectinid mollusc. The ecological role of polyclads is still little known, and experiments are lacking. However, it shows that native flatworm species are interacting with Nodipecten nodosus in experimental aquaculture, feeding either on the molluscs or on the associated fauna. [ABSTRACT FROM AUTHOR]

In the estuary of the Volchanka River, Vostok Bay, Sea of Japan, the Japanese mud shrimp Upogebia major forms a population in the upper sublittoral zone at depths of 0.5-3 m in slightly silted sand. This population covers both open coastal bottom areas and a belt of the eelgrass Zostera marina, which is oriented parallel to the shoreline. The population density and biomass of the mud shrimp, as estimated by the abundance of holes on the ground surface, averaged 5.3 ± 4.6 ind./m and 36.46 ± 16.74 g/m, respectively, and those calculated from the total sampling at counting sites were 4.2 ± 2.6 ind./m and 28.90 ± 17.89 g/m, respectively. The biomass of the macrozoobenthos, which consisted of nine taxa, reached 87 g/m. Bivalves dominated in the community by biomass and slightly surpassed crustaceans, among which U. major dominated (33.2-41.9% of the total biomass of the macrozoobenthos). [ABSTRACT FROM AUTHOR]

In August and October of 2013, the patterns of the spatial distribution, size, and sex composition of the estuarine population of the ghost shrimp Nihonotrypaea japonica were studied in the Vostok Bay (Peter the Great Bay, Sea of Japan) for the first time in Russian waters. It was found that this species inhabits waters under monthly mean temperatures from −1.6 to 21.7°C and salinity from 11.2 to 32.5‰, populating silted sand below the ice cover that is typical for December-March. The maximum population density of N. japonica reached almost 200 ind./m, and a biomass of 120 g/m with average values of these parameters of 18 ± 43 ind./m and 10.83 ± 25.50 g/m, respectively, which is almost one-third of the total biomass of the macro-zoobenthos. The population consisted of males with body lengths of 14-61 mm and females from 17 to 58 mm. In the size composition four groups of individuals were distinguished: underyearlings, 1-, 2-, and, apparently, 3-year old animals. The male/female ratio is close to 1 : 1.2. Males prevailed in animals with body lengths of less than 20 mm, while females prevailed among larger individuals. Features of the spatial distribution, size, and sex composition of populations of N. japonica are discussed in relation to the environment and reproduction at the northern boundary of its range. [ABSTRACT FROM AUTHOR]

Patterns of long-term changes in fouling communities developing on artificial substrates in the White Sea are reviewed. The most significant shifts occurring in these communities are caused by biological successions that can last for several decades. Terminal stages of succession are the communities of a mussel Mytilus edulis or a solitary ascidian Styela rustica which can periodically replace one another within a narrow range of depths: from 1-1.5 to 5 m. Sporadic local invasion of a sponge Halichondria panicea can transiently modify the composition and performance of fouling communities. Sudden invasion of species that are not a typical component of fouling communities (infaunal polychaetes and molluscs, crabs) is not rare phenomenon but these organisms do not play a significant role there. Representatives of the associated polychaete fauna in fouling communities show long-term cyclic fluctuations in their abundances. Duration of these cycles is 7-8, 11-14, or 20 years. [ABSTRACT FROM AUTHOR]

Coral reef cryptofauna forms an important component of tropical marine biodiversity, consisting primarily of invertebrates dwelling in and on corals. During a survey carried out around the Semporna peninsula (Sabah, NE Borneo), the occurrence of gall crabs inhabiting mushroom corals was examined on reefs ranging from sheltered to exposed conditions. Out of 44 fungiid species, 19 were found to be associated with gall crabs. The gall crabs were observed at 85 % of the 62 studied sites, and their occurrence rates per site ranged between 0 and 25 %. High occupancy rates were almost equally distributed over the northern (sheltered) and southern (exposed) sites. Sites without gall crabs were all wave-exposed and predominantly under the influence of disturbances, such as blast fishing or relatively high nutrient loads. [ABSTRACT FROM AUTHOR]

Interactions between macroalgae and their associated fauna are of great interest for marine invasions, because fauna may increase the biotic resistance of a system and macroalgal invasions may cause shifts in faunal composition. We tested for differences in faunal community structure between a macroalgal invader, Sargassum muticum, and several native macroalgae in intertidal pools on both the west and south coast of Portugal. On each coast, we compared the faunal diversity and composition associated with the invader with that of the competing native macroalga(e). On the west coast, the diversity of the fauna associated with S. muticum was equal to or lower than with the native competitor, Cystoseira humilis. Fauna composition differed between S. muticum and C. humilis at both locations, but within each species, no differences between locations were detected. In contrast, the fauna diversity on S. muticum of the south coast varied among locations. S. muticum fauna differed from the fauna of all native macroalgae at one location, but only from three out of seven native macroalgae at the other location. Discriminating fauna species did not show a consistent pattern towards higher or lower abundances in S. muticum compared to most native macroalgae, and species-specific contributions were small. Differences in fauna community also depended on the identity of the native macroalga. In conclusion, the fauna associated with S. muticum differs from many native brown macroalgae, but these differences were not consistent as they depend both on the native macroalgal species and on location. This invader does not seem to have a severe negative impact on local macroalgae-associated fauna. [ABSTRACT FROM AUTHOR]

Macrophytes increase structural complexity in aquatic ecosystems and their emergent structures provide habitats for spiders. We sampled spiders in three species of macrophytes ( Eichhornia azurea, Eichhornia crassipes and Limnobium laevigatum) and measured five traits indicative of structural complexity: horizontal structure, vertical structure, plant height, macrophyte richness and macrophyte biomass. We tested the hypothesis that spider density and diversity increase and guild composition changes along a gradient of structural complexity provided by macrophytes. Vertical and horizontal structure and macrophyte richness covaried with the attributes of spider assemblages. However, vertical structure was an important habitat-complexity trait because it covaried with all spider attributes investigated, positively affecting density and taxa richness and changing guild composition. Our findings suggest that the increase in macrophyte structural complexity, primarily through vertical structure, provides additional habitat and microhabitat variability. These forms of variability may increase the availability of prey and shelter and even reduce intraguild predation between spiders, thereby potentially increasing density and taxa richness. Moreover, an increase in vertical complexity provides available structures for web attachment, favoring web-building spiders and consequently affecting guild composition. Thus, habitat structure plays an important role in structuring spider assemblages and specific traits may mediate changes in particular attributes of spider assemblages. [ABSTRACT FROM AUTHOR]

This study describes the distribution and abundance patterns of the associate fauna on the living surface of the corals Siderastrea stellata Verril, 1868 and Mussismilia hispida (Verril 1902) using a non-destructive method, on the northern coast of Rio de Janeiro State. For each coral species, infestation density and proportions of infested colonies, colonies attached and unattached to the substrate were estimated. A total of 474 colonies of S. stellata and 452 colonies of M. hispida were examined. The barnacle Ceratoconcha floridana (Pilsbry, 1931) was the dominant coral associate found, followed by gall-crabs of the family Cryptochiridae Paulson, 1875 and the bivalve Lithophaga bisulcata (d’Orbigny, 1842). Both coral species presented similar patterns of infestation dominance. S. stellata colonies were more commonly infested and showed a greater mean infestation density of 0.62 ind/cm2 at Armação dos Búzios, whereas M. hispida colonies had infestation densities of only 0.20 ind/cm2. Infestation density does not appear to impact negatively on corals of Armação dos Búzios. A clear negative relationship between the number of associates in the coral colony and coral size was found. Evidently abundance and frequency of occurrence of associated fauna is highly related to coral community structure and composition and the results highlight the importance of local scale studies. [ABSTRACT FROM AUTHOR]

The aims of this study were to investigate the structure and composition of the invertebrate community during the detritus decomposition (colonization features) of the two most abundant aquatic macrophytes Typha domingensis Pers. and Nymphaea ampla in Jurubatiba Lagoon and verify if the chemical composition of the substratum has any influence on invertebrate colonization and which are the functional groups possibly affected by these compounds. The substratum T. domingensis had higher percentages of cell wall fraction (F = 108.33; p < 0.0001) and organic matter (F = 225.77; p < 0.0001), while nitrogen (F = 408.61; p < 0.0001) and phosphorus (F = 224.59; p < 0.0001) contents were higher in N. ampla. These differences in the chemical composition of the substrata influenced the decomposition rate, and the detritus of N. ampla (4.37% DW day-1) decomposed approximately 26 times faster than the T. domingensis (0.17% DW day-1) detritus. The main groups of invertebrates that colonized both substrate were Chironomidae, with more than 50% of the total, followed by Oligochaeta, Nematoda, Copepoda and Cladocera. The results showed that the slow breakdown rate of T. domingensis detritus provided a higher probability for colonization and that the main driving force structuring the invertebrates' community was degradative ecological succession (DES). [ABSTRACT FROM AUTHOR]

This paper advances a qualitative and quantitative preliminary characterization of the mollusc fauna associated with the submerged roots of Rhizophora mangle L. in three mangrove areas with different degrees of anthropogenic impact in the San Andres (Hooker and Honda Bays) and Providence (Old Providence McBean Lagoon National Park) archipelago in the Western Caribbean. The study was carried out during the dry and rainy seasons (July and November, respectively) back in 1998. Samples were taken from 34 submerged roots which were not fixed to the substrate. Several physico-chemical parameters were also measured in situ. All molluscs were identified and counted and indexes of species richness, diversity, uniformity, similarity, dominance of species and density of individuals were calculated. All in all 5,771 individuals belonging to 21 species of 17 families were counted. Most of the species were epibenthic, herbivorous and with undifferentiated planctonic larvae, but most of the individuals were epifaunal and attached as well as filter-feeders with planctonic larvae. Most individuals were found in juvenile stages. The three sites, under different degrees of anthropogenic impacts, showed related values of species richness, diversity and abundance, as well as densities of mollusc taxa in oceanic communities associated with mangrove roots. Further research should be done to find similar responses in accompanying significant groups, such as Crustacea and Polychaeta. [ABSTRACT FROM AUTHOR]

This study records the polychaetes found on the submerged roots of Rhizophora mangl on San Andres and Providence Islands, Colombian Caribbean. Sampling was done in 1998 during the rainy (July) and dry (November) seasons; each season, 17 roots were collected in three different stations with different kinds of human impact, two in San Andres and one in Providence. At the same time temperature, salinity and dissolved oxygen were measured in situ. Aromatic hydrocarbons were measured in the laboratory. The polychaetes were removed from the roots and identified. The available root area for the organisms was also measured. Five genera and 11 species were newly recorded for the Colombian Caribbean. The most abundant families were Terebellidae in Old Providence Mc Bean Lagoon, Syllidae in Honda Bay and Nereididae in Hooker Bay on the San Andres Island. Thelepus `setosus' (Terebellidae) and Amblyosyllis sp. (Syllidae) were highly abundant in less polluted sampling stations such as Old Providence Mc Bean Lagoon and Honda Bay. On the other hand, Neanthes `succinea' (Nereididae) were abundant in Hooker Bay which was the most polluted station. Salinity seemed to be the most important parameter for the polychaete populations. The populations of polychaetes, as a total group, seemed to be related to the root area available on both islands, independent of the season. However, during the rainy season, the populations were independent of root area availability, while during the dry season, the populations were dependent on it. [ABSTRACT FROM AUTHOR]