Rocky Substrate Research Articles

Inventory of Seaweeds in Selected Municipalities in the Balicuatro Area of the Province of Northern Samar, Philippines

Seaweeds or marine macroalgae is one of the marine resources that are understudied in the province of Northern Samar, the province have twenty-four (24) municipalities and twenty (20) of them have coastal zone which is ideal for marine researches as well as for aquaculture. This study is focused on the present seaweeds in the three (3) selected municipalities in Balicuatro area in the province of Northern Samar. A total of ninety-four (94) taxa were collected/ found in the three (3) sampling sites. Lavezares got the greatest number of seaweeds with sixty (60) taxa, followed by Biri with fourty-four (44), and the least was in Allen with thirty-four (34) species. Chlorophyta have thirty-nine (39) species which constitute for 39.36% of the total identified seaweeds, followed by thirty-four (34) red seaweeds (36.17%), and, lastly, Brown macroalgae with only twenty-three (23) species which accounts for 24.47%. The most common marine macroalgae in all sampling sites were: Hormophysa cuneiformis which was found in ten (10) sampling sites, followed by Halimeda macroloba, Ulva reticulata, and Sargassum oligocystum which were found in ten (10) sampling sites. In terms of environmental parameters, temperature and salinity of all sampling sites were tested to be within the normal range during the collection period based on established threshold limit. However, in terms of pH, it was detected that two (2) barangays/ sampling sites in Lavezares, namely: Balicuatro and San Juan which only had 7.2 and 7.4 which is below the threshold limit range of seawater pH which is 7.5-8.5. In terms of substrate, rocky substrate is common to all sampling sites which indicates that hard substratum is preferable for the growth, adaptation, and survival of seaweeds.

The Multiphasic Teeth of Chiton Articulatus, an Abrasion‐Resistant and Self‐Sharpening Tool for Hard Algae Collection

AbstractChiton articulatus is a species of mollusk living in the tropical Pacific intertidal rocky shores of Mexico. This species feeds on solid waste organic sources, including hard crustose algae that grow on rocky substrates, by grazing on them with its radula, a flexible chitinous membrane lined with mineralized major lateral teeth. In this study, the composition, morphology, and resulting mechanics of the mature teeth of this species, which have yet to be examined, are revealed. The results show the presence of multiphasic mature teeth, each consisting of aligned hard magnetite nanoparticles on the leading edge of the tooth underneath which are magnetite lamellae, followed by goethite, lepidocrocite, and eventually hydroxyapatite near the trailing edge. This multiregional structure demonstrates a gradation in hardness as well as different microstructural features integrated with tough interfaces. The combination of these microstructural and phase arrangements results in an abrasion‐resistant tough structure with a self‐sharpening ability. The results of this work will help contribute to developing new bioinspired designs while also helping to understand the evolution and feeding habits of these intriguing invertebrates.

Untangling Coastal Diversity: How Habitat Complexity Shapes Demersal and Benthopelagic Assemblages in NW Iberia

Understanding species–habitat relationships is essential for ecosystem-based conservation. This study explores the significance of habitat characteristics and complexity for demersal and benthopelagic communities within a patchwork of coastal habitats, including rocky seabed, macroalgae formations, sandy bottoms, and a combination of rock and sand areas. Species and habitats were surveyed along the north-west (NW) Iberian continental shelf area of Viana do Castelo using baited remote underwater video stations (BRUVS). We found significant differences (p < 0.05) in species assemblages across habitats, with rocky substrates showing the highest diversity and abundance. Sand habitats showed the lowest species richness and abundance, underscoring the importance of habitat complexity to support marine life. Our study also emphasises the role of specific species in shaping the communities, identifying key species such as Trisopterus luscus, Diplodus vulgaris, and Ctenolabrus rupestris as the three most abundant in the region and significant contributors to the observed dissimilarities between habitats. By elucidating the impact of habitat complexity on marine life, our results offer essential baseline data, which serve as a kick-start point to inform sustainable management and conservation strategies for the long-term health and productivity of these vital ecological systems in the North-East Atlantic.

The Molecular Profile of Soil Microbial Communities Inhabiting a Cambrian Host Rock.

The process of soil genesis unfolds as pioneering microbial communities colonize mineral substrates, enriching them with biomolecules released from bedrock. The resultant intricate surface units emerge from a complex interplay among microbiota and plant communities. Under these conditions, host rocks undergo initial weathering through microbial activity, rendering them far from pristine and challenging the quest for biomarkers in ancient sedimentary rocks. In addressing this challenge, a comprehensive analysis utilizing Gas Chromatography Mass Spectrometry (GC-MS) and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) was conducted on a 520-Ma-old Cambrian rock. This investigation revealed a diverse molecular assemblage with comprising alkanols, sterols, fatty acids, glycerolipids, wax esters, and nitrogen-bearing compounds. Notably, elevated levels of bacterial C16, C18 and C14 fatty acids, iso and anteiso methyl-branched fatty acids, as well as fungal sterols, long-chained fatty acids, and alcohols, consistently align with a consortium of bacteria and fungi accessing complex organic matter within a soil-type ecosystem. The prominence of bacterial and fungal lipids alongside maturity indicators denotes derivation from heterotrophic activity rather than ancient preservation or marine sources. Moreover, the identification of long-chain (>C22) n-alkanols, even-carbon-numbered long chain (>C20) fatty acids, and campesterol, as well as stigmastanol, provides confirmation of plant residue inputs. Furthermore, findings highlight the ability of contemporary soil microbiota to inhabit rocky substrates actively, requiring strict contamination controls when evaluating ancient molecular biosignatures or extraterrestrial materials collected.

Diversity of Rock-Inhabiting Fungi in Tarragona Province, Spain.

Rock-inhabiting fungi (RIF) are usually extremely tolerant or extremophilic, as they can survive on natural and artificial rocks despite being exposed to stressful conditions. RIF have serious negative effects on the appearance and cohesion of rocky substrates, causing the alteration and decomposition of building materials, but also on human and animal health, as they can act as opportunistic pathogens. Their identification is therefore of great importance, especially in urban areas. In the present study, culturing techniques for isolating fungi, and a polyphasic taxonomic approach to their identification, were used to assess the diversity of micromycetes that darken the surfaces of buildings in various villages and cities in Tarragona Province (Spain). Sixty-four species of RIF belonging to forty-one genera were identified, including a new genus (Coccodomyces) and the following six new fungal species: Coccodomyces pleiosporus, Exophiala caementiphila, Exophiala multiformis, Neocatenulostroma spinulosum, Neodevriesia longicatenispora, and Paradevriesia holothallica. Thus, we have established that building materials are ecological niches where a high biodiversity of RIF can develop.

Cystoseira compressa and Ericaria mediterranea: Effective Bioindicators for Heavy- and Semi-Metal Monitoring in Marine Environments with Rocky Substrates.

Marine environmental monitoring is essential to ensure that heavy-metal (HM) concentrations remain within safe limits. Most seawater analyses currently consider sediment or water samples, but this approach does not apply to rocky substrates, where water samples can only indicate immediate contamination. We used two common Mediterranean algae species, Cystoseira compressa and Ericaria mediterranea, as bioindicators living in the intertidal zone on rocky substrates along the seacoast. HM concentrations were assessed over a one-year period in the perennial base crust and in the seasonal frond, considering marine sites characterised by different contamination risks. Both algae showed that HMs accumulate mainly in the perennial base rather than in the seasonal frond. Furthermore, the algae species always showed a different order of bioaccumulation factors: Cd > Ni > Pb > Cr > Cu > Mn > Zn for the frond and Pb > Cr > Ni > Cd > Mn > Cu > Zn for the base. Our study shows that C. compressa and E. mediterranea accumulate HM consistently with the types of sites analysed and differentially with respect to the part of the thallus. These results demonstrate that these algae can be effectively used as reliable bioindicators to assess the presence of HM in marine environments with rocky substrates, providing both short- and long-term monitoring.

Abiotic correlates with diversity and distinctiveness in Sunshine Coast heathlands: Moisture, volcanic landscapes and patterned mounds

AbstractThe ongoing management and protection of conservation areas can be informed by understanding factors that affect the integrity of these communities. Abiotic factors associated with diversity and phylogenetic dispersion within communities, as well as distinctiveness between communities, may potentially be impacted by climate change or changes in hydrology due to urbanization. This study used a range of diversity metrics, along with nominal and quantitative abiotic data, to examine correlates with diversity patterns in the Sunshine Coast heathlands, ecosystems under threat from urban development. Metrics for 80 heathland sites over a variety of substrates, moisture levels and topographic factors were compared using univariate and multivariate statistics. Moisture is a key abiotic factor correlated with the diversity and distinctiveness of heath, and also with higher phylogenetic dispersion of moist and wet sites, indicating possible refuges. Vegetation composition patterns were distinct in the heaths on Tertiary and Triassic rocky volcanic substrates, with the overlapping composition of heath on other substrates, confirming the tolerance of many heath species to a variety of substrates. Patterned natural ‘mounds’ and ‘trenches’ were associated with phylogenetic evenness and are possible refugia. Multivariate analysis had a weak positive correlation of environmental factors with vegetation and phylogenetic composition, emphasizing the complexity of correlates with diversity for the heathlands. This study suggests that both the management of hydrological changes and protection of potential refugial areas are likely to be critical in maintaining the integrity and diversity of the Sunshine Coast heathlands.

A new family of Asellota (Crustacea, Isopoda) from the deep sea of Zealandia

A new family-level taxon of deep-sea isopods, Basoniscus hikurangi gen. et sp. nov., was recovered from the Hikurangi Plateau in the deep sea off eastern New Zealand. The broad-bodied, eyeless, seemingly unremarkable isopod was unusual in its possession of features that characterize two different families: the shallow water Joeropsididae Nordenstam, 1933 and the deep-sea Haploniscidae Hansen, 1916. An analysis of superfamily Janiroidea G.O. Sars, 1897 was conducted to establish the affinities of the species. Multiple analyses were done using unweighted and implied weighted characters. Existing families were well supported, with B. hikurangi intermediate between Joeropsididae and Haploniscidae. The new species, however, cannot be placed in either family owing to its lack of important defining synapomorphies of each family. As a result, Basoniscidae fam. nov. was created to contain this new species. That rocky hard substrates are undersampled is another implication. Our understanding of deep-sea species richness will not be accurate until more efforts are made to survey these habitats, especially more sites in the southern hemisphere. These gaps in our knowledge of the deep sea impairs any general claims about the distribution of biodiversity on a global scale. This find demonstrates that museums hold underused but valuable resources for understanding and describing the biodiversity of the deep sea.

The role of aquaculture in the international trade of giant clams (Tridacninae) for the aquarium industry (2001–2019)

An overview over the international trade in live giant clams (Bivalvia: Tridacninae) from 2001 to 2019 was made based on worldwide import data from the CITES Trade Database. A distinction was made between trade records of wild-caught clams and maricultured ones. A general decline in the trade of wild giant clams was observed. Since these bivalves naturally live attached to rocky substrate in coral reefs and their forceful removal is harmful to surrounding corals, this trend helped to prevent damage to their natural environment. Possible reasons behind this decline are lower population numbers, trade restrictions, and a decrease in demand. Trade in wild-caught Tridacna crocea decreased, whereas that of T. maxima increased, taking over the former's position as most popular species. From 2015 onwards, over 50% of the source was made up by aquaculture, up to 2019. Aquaculture of live giant clams can be profitable, but there are still obstacles to overcome in order to ensure stable production numbers and long-term profit. With more research and support from governments, aquaculture can help to take pressure off wild populations of giant clams that are already suffering from exploitation for the sea-food market and souvenir industry, and also from habitat degradation due to climate change and other anthropogenic disturbances.

Macroalgal community structure and composition in intertidal zone of Sarangan Beach, Gunungkidul, Indonesia

The intertidal zone of Sarangan Beach is characterized by rocky substrates and it has high macroalgae biodiversity. However, based on previous research, limited research was conducted at the location on the changes of macroalgae community structure. This research aims to study the structure and composition of macroalgae communities in the intertidal zone of Sarangan Beach and the physicochemical factors that affect its growth. Data was collected in September 2023, during the maximum low tide. The data collection was done by systematic sampling method using 60 plots 1x1 m2. The physicochemical parameters were measured and observed i.e. water and air temperature, pH, salinity, light intensity, and substrate type. The results showed 23 species of macroalgae were found in the intertidal zone of Sarangan Beach, consisting of 8 species of Chlorophyta, two species of Phaeophyta, and 13 species of Rhodophyta. The highest abundance was shown by Ulva lactuca, followed by Sargassum crassifolium and Kappaphycus alvarezii, while the lowest was Gracilaria spinulosa. The structure of the macroalgae community consists of moderate diversity (H’=1.97) with high uniformity (E=0.63) and low dominance (C=0.27). This is influenced by physicochemical parameters, especially water and air temperature, pH, and substrate condition.

Distribuição do ictioplâncton determinada por diferentes ambientes em uma lagoa costeira de água doce

Abstract Aim This study aimed to evaluate the spatial and temporal distribution of ichthyoplankton in the Peri Lagoon, a coastal freshwater lagoon in Brazil. Methods Ichthyoplankton samples were collected every two months from June 2008 to April 2010 with 500 µm conical-cylindrical planktonic nets at five sampling stations. Results In total, 181 fish eggs and 1,315 larvae, representing estuarine and freshwater species, were captured. The most representative species were Awaous tajasica, Ctenogobius sp1, and Platanichthys platana. Significant differences were found in temporal egg distribution and larval spatiotemporal distribution (Kruskal-Wallis test, p < 0.05). Eggs were predominantly captured during the autumn, winter, and spring Neotropical seasons. Geospatial analysis demonstrated spatial segregation in the distribution of larval assemblages, with higher abundances in areas adjacent to riparian forests, following stream mouths, and deeper areas with rocky substrates. Conclusions Proximity to streams and areas surrounded by dense forests is crucial for the spawning and development of fish species in the Peri Lagoon. The findings of this study provide valuable insights into the conservation of the ichthyofauna in this unique environment.

Feeding ecology of wintering Great Northern Divers Gavia immer in Argyll, Scotland

I investigated the role of tide and time of day on feeding success and prey species of the Great Northern Diver Gavia immer at its wintering grounds in Argyll, Scotland. Focal animal sampling was used on solitary divers to determine their activity during different tidal states and at different times across four main sites. When a bird performed ten successive dives, feeding success was recorded and inferred. Divers spent more time feeding early in the morning in comparison to other periods of the day. Less time was spent feeding at high tide, but this difference was not statistically significant. Divers spent 55% of the daylight period feeding, with most of this feeding time spent underwater. Prey was brought to the surface during 15% of dives and birds drank (thought to indicate ingestion of prey underwater) following 33% of dives. Crabs and flatfish were the main observed prey items, with 61% of the prey brought to the surface estimated to have a mass of less than 5 g, although items up to 80 g were consumed on occasion. The composition of prey brought to the surface varied between sites, with more crab prey items seen on sites with rocky substrates. I investigated differences in the feeding behaviour of adult and first-winter Divers at one site, but observed few differences. The importance of high-quality feeding sites for Great Northern Divers, and the implications of time spent underwater within current census techniques are discussed.

Spread of the invasive corals, Tubastraea coccinea and Tubastraea tagusensis, towards the lower intertidal zones of southeastern Brazil

Photographs were obtained of two invasive species of sun corals (Tubastraea tagusensis and Tubastraea coccinea) covering rocky substrates, in Ilha Grande Bay, Rio de Janeiro/Brazil, that are exposed, out of seawater, during low tide. The images highlight secretion of mucus, distention of tentacles, and partial loss of soft tissue.

Taxonomic and functional diversity of subtidal benthic communities associated with hard substrates at Crozet archipelago (sub-Antarctic, Southern Ocean)

Sub-Antarctic coastal marine ecosystems harbor rich and diverse benthic communities. Despite their ecological uniqueness and vulnerability to global changes, studies on benthic communities remain limited. Using underwater video-imagery, we investigated the taxonomic and functional diversity of benthic communities associated with hard substrates at Baie du Marin (Ile de la Possession, Crozet archipelago). The Baie du Marin species richness and diversity were additively partitioned to evaluate spatial patterns of species through the following spatial scales: within images, among images within transects, and among transects. We analyzed imagery data from seven transects located at different sites inside Baie du Marin and covering contrasting natural rocky habitats and underwater artificial cable substrates. A total of 50 faunal (mainly represented by Echinodermata and Porifera phyla) and 14 algae (mainly represented by Rhodophyta phylum) taxa were identified. Rocky substrates were dominated by high densities of the polychaetes Parasabella sp. and Lanice marionensis, whereas submarine cables were dominated by high densities of the bivalve Kidderia sp. attached to macroalgae. Our results show contrasted distribution patterns in the faunal and algal assemblages within the Baie du Marin, with significant ecological differences between submarine cables and natural rocky substrates. Larger spatial scale (i.e., among transects) accounted for most of the bay richness and diversity, highlighting a high-level of habitat heterogeneity within the bay. Through a trait-based approach, our findings revealed that Crozet benthic communities are characterized by low functional richness, evenness, and redundancy, highlighting a potential vulnerability to current and future natural and anthropogenic changes. This study provides a novel bentho-ecological baseline for future assessments of natural and anthropogenic impacts on the marine environment of the Crozet archipelago; and for the conservation management of these remote habitats that make part of the French Southern Territories Marine Protected Area, recently inscribed on the UNESCO World Heritage list.

Edible Sea urchin (Paracentrotus lividus) larval dispersal and connectivity modelling in the northwestern Mediterranean Sea

The edible sea urchin (Paracentrotus lividus) is of significant economic importance due to high demand for its consumption in various Mediterranean countries. This echinoderm plays a crucial ecological role by regulating the dynamics of seaweed and seagrass through its grazing behaviour. The abundance of sea urchin is variable in time and space, but it is currently potentially declining in the Mediterranean Sea, and likely to be negatively affected by global change. Therefore, gaining a more comprehensive understanding of sea urchin larval dispersal patterns over an extended period could contribute to our understanding of how their dynamics relate to population connectivity. To investigate the trajectories of larval dispersal of this sea urchin in the Northwestern Mediterranean Sea, we combined a Lagrangian model (Ichthyop) with a hydrodynamic model (MARS3D). This study covered the years 2010–2018 and aimed to quantify the connectivity between the preferred habitats of the sea urchin (seagrasses and rocky substrates). The present study explores seasonal variations in dispersal routes and habitat connectivity relationships for two spawning scenarios identified in the literature (spring and autumn). The results enable us to identify dispersal routes, and their regularity over time. They highlight a consistent connection between Sardinia, Corsica, and the coastlines of the Ligurian and Tyrrhenian Seas, indicating a lack of genetic structuring within the edible sea urchin population in this area, particularly in Corsica. The connectivity matrices confirm the observed dispersal trajectories and highlight certain areas of significant and enduring local retention over time. The results also reveal minimal seasonal variability. Conversely, interannual variability appears pronounced, particularly in relation with trends in the warming of surface waters in the Mediterranean, which seem to impact the dispersal routes taken by P. lividus larvae. Lastly, a connectivity map was created to explore spatial resource management perspectives, aiming to identify frequent connections over an extended time period and assign varying levels of intensity to them. This approach can provide guidance with regard to resource management issues for different coastal areas that can be connected by larvae.

Polychaetes (Annelida: Polychaeta) off Kyky (Black Sea, Trkiye) with descriptions of three new species.

The examination of benthic materials collected in September 2022 at six stations off Kyky (south-west coast of the Black Sea, Trkiye) both on hard (three stations) and soft substrata (three stations) at depths ranging from 8 and 27 m revealed a total of 57 polychaete species belonging to 22 families. Among the species, the polynoid Malmgrenia polypapillata is a new record for the Black Sea fauna, and three species belonging to the Syllidae (Erinaceusyllis defneae n. sp.) and Terebellidae (Polycirrus karadenizicus n. sp. and P. rhombolabiatus n. sp.) are new to science. Algae dominated (Cystoseira cinita, Cladophora sp. and Phyllophora crispa) rocky substrata had 30 polychaete species and a maximum polychaete density of 7325 individuals/m2, while soft bottom substrata (fine sand and muddy sand with shell fragments) possessed 38 species and a maximum polychaete density of 3520 individuals/m2. The family Nereididae (3176% of the total number of individuals), and the species Platynereis dumerilii and Polyphthalmus pictus dominated hard bottom stations, whereas the families Nephtyidae, Spionidae and Dorvilleidae, and the species Micronephthys longicornis, Protodorvillea kefersteini and Prionospio maciolekae were represented by high number of individuals at soft-bottom stations.

Deep octopod habitat in the western North Atlantic characterized by Standard Ecological Classification from videos

AbstractHabitat characterization is important to assess fully the niches of different organisms. There is a large knowledge gap regarding habitat use by deep‐sea benthic incirrate octopods, partly due to their assumed preference for hard‐to‐sample rocky substrata. This study uses observations from in situ videos recorded by remotely operated vehicles (ROVs) deployed from the NOAA Ship Okeanos Explorer and implements the Coastal and Marine Ecological Classification Standard (CMECS) to describe the habitat of three common species of bathyal incirrate octopods living in the western North Atlantic Ocean: Bathypolypus bairdii (Verrill 1873), Graneledone verrucosa (Verrill 1881), and Muusoctopus johnsonianus (Allcock, Strugnell, Ruggiero, & Collins 2006). Significant differences in species' preferences for geoform setting, depth, and substrate type were found. All three species are most likely to be observed by ROV in a submarine canyon and least likely to be seen on a seamount. B. bairdii was found shallower than G. verrucosa and M. johnsonianus. This is the first study of its kind using CMECS to classify the habitat of specific organisms as opposed to the habitat types in a specific area.

Description of the fifth sea pen species that attaches to hard substrates by modifying its peduncle

Almost all sea pens inhabit soft bottoms, but only four species are known to live on rocky substrates. These are all deep-sea species with specialized sucker-like peduncles considered to attach to rocky substrates. Their known distribution is very sparse due to the limited number of reports. In this study, we describe a novel rock-inhabiting sea pen, Anthoptilum gnome sp. nov., from a deep-sea marine protected area in Japan, along with the first report of the mitochondrial genome of a rock-inhabiting species and a rock-inhabiting species from the northwestern Pacific Ocean. The mitogenomic information provides insight into their evolutionary aspect; A. gnome sp. nov. may have acquired the sucker-like peduncle within the phylogenetic constraints in the genus and the sucker-like peduncle may be the character obtained independently in Pennatuloidea.

Stigonema lichenoides sp. nov. (Nostocales, Сyanobacteria): новый вид, выделенный из лишайника Ephebe lanata

A new cyanobacterium species Stigonema lichenoides Patova, Novakovskaya, Shalygin et Shadrin, sp. nov., a photobiont of the cyanolichen Ephebe lanata, has been described. The samples were collected from rocky substrates in the mountain tundra of the Northern Urals. A detailed morphological description is given and differences between this species and related taxa of the genus Stigonema are discussed. A molecular phylogenetic analysis of the studied samples was performed using 16S–23S rRNA sequences. The correlation of morphological and molecular data, as well as the comparison of the sequences obtained from the samples with data available in the NCBI database, allowed the identification of a new species of the genus Stigonema.

Seasonal and environmental dynamics of intra-urban freshwater habitats and their influence on the abundance of Bulinus snail host of Schistosoma haematobium in the Tiko endemic focus, Mount Cameroon region.

Urogenital schistosomiasis (UGS) caused by Schistosoma haematobium is endemic in the South West Region of Cameroon. An understanding of the abundance and distribution of the Bulinus snail, intermediate host can inform strategic snail control programmes at a local scale. This study investigated seasonal dynamics and environmental factors influencing occurrence and abundance of freshwater snail intermediate hosts in Tiko, a semi-urban endemic focus in the Mount Cameroon area. A longitudinal malacological field survey was conducted between December 2019 and December 2020 in the Tiko municipality. Snails were collected for one year monthly at 12 different human water contact sites along a stretch of the Ndongo stream using a standardized sampling technique. Freshwater snails were identified using shell morphological features. In addition, water temperature, pH, electrical conductivity, total dissolved solutes, salinity, water depth, width and flow velocity were measured, and vegetation cover as well as substrate type were determined. Bayesian regression models were used to identify the main environmental factors affecting the occurrence and abundance of Bulinus intermediate host. In total, 2129 fresh water snails were collected during the study period. Physa (51.4%) was the most abundant genus followed by Melanoides (28.6%) then, Bulinus (15.5%), Lymnaea (4.2%), Indoplanorbis (0.2%) and Potadoma (0.1%). Seasonality in abundance was significant in Bulinus sp as well as other genera, with greater numbers in the dry season (peaks between December and February). Water temperature, a rocky or sandy substrate type associated positively with Bulinus sp, meanwhile a higher water flow rate and medium vegetation negatively influenced the snail intermediate host population. These findings underscore the importance of timing behavioural and snail control interventions against schistosomiasis as well as increase vigilance of other trematode diseases in the study area. The continuous spread of planorbid snail hosts is a major concern.