Macroinvertebrate Fauna Research Articles

Distribution of benthic macroinvertebrates across a reed stand in a brackish Baltic lagoon

The role of reeds in the functioning of ecosystems and their significance for zoobenthos in the coastal lagoons is poorly understood. We hypothesise that next to the spatial zonal differentiation of abiotic factors in the apparently homogeneous habitat of reeds, benthic macroinvertebrate fauna is also unevenly distributed, and differs in taxonomic and functional diversity, as well as density and biomass across the reed stand. The research was carried out in the Vistula Lagoon (southern Baltic) along three designated sectors arranged parallel to the shoreline and differing in distance from the shore and depth. Mean density of reed stems in the analysed stand was within the range of values reported from different American and European wetlands. Regardless of the location within the reeds and the season, the fauna was dominated by detritivorous Tubificinae and larvae of Chironomidae. The highest diversity, density, and biomass of fauna were found in the middle littoral zone, and the lowest in the outer zone adjacent to the open water. The presented data support our hypothesis predicting the existence of a spatial variation pattern in the composition and distribution of macroinvertebrates in response to the changing zonal habitat conditions within the reed stand.

A Study of Benthic Macroinvertebrate Fauna in a Tributary of Himalayan River Bhilangana, Uttarakhand, India

The present study is focused on structural and functional composition of benthic macroinvertebrate fauna in the river Nailchami, a tributary of Bhilangana River. The seasonal samples were collected during March 2018 to February 2019 at three different stations (S1, S2, and S3) by lifting of stones and sieving of soft substrate (0.5 mm mesh size) from marked area (1ft square). Standard procedures were adopted to identify and analysis for preserved samples. The physico-chemical parameters varied among the stations. The total mean density varied seasonally at each station and found significantly different. The highest density was found in winter season followed by summer and monsoon. Fifty-eight invertebrate families were recorded among all the stations. Simulidae was most abundant family at all stations during summer season (S1-17.5%, S2-6.8%, S3- 11.3%). However, in the monsoon season, chironomidae was abundant at S1 (22.8%) and S3 (10.6%), while limnephilidae (16.2%) at S2. In winter season, stations S1, S2 and S3 were dominated by chironomidae (48%), limnephilidae (12.4%) and simulidae (16.7%), respectively. PCA ordination techniques identified characteristic benthic macroinvertebrate taxa at different stations. Gathering collectors were most abundant functional feeding groups at all stations as well as seasons. Thus, river indicated heterotrophic status along the river length.

Contribution to the knowledge of the aquatic macroinvertebrate fauna of Bükkösdi-víz (Mecsek Mountain, SW Hungary)

In 2018 and 2019, quantitative aquatic macroinvertebrate samplings were carried out in the river network of the Bükkösdi-víz (Mecsek Mountain). The identification of 325,865 macroinvertebrate specimens originated from 40 sampling sites resulted in the occurrences of 125 different species belonging to 12 higher taxa (Gastropoda – 9, Bivalvia – 1, Hirudinea – 4, Malacostraca – 6, Ephemeroptera – 16, Odonata – 12, Plecoptera – 3, Heteroptera – 19, Coleoptera – 23, Megaloptera – 3, Neuroptera – 1, Trichoptera – 28), including 8 protected (Bivalvia: Unio crassus, Odonata: Calopteryx virgo, Coenagrion ornatum, Gomphus vulgatissimus, Onychogomphus forcipatus, Orthetrum brunneum, Heteroptera: Aquarius najas, Neuroptera: Osmylus fulvicephalus) and 1 strictly protected species (Odonata: Cordulegaster heros).

Dinaric karst intermittent rivers harbour some rare mayflies (Insecta, Ephemeroptera)

While investigating the aquatic macroinvertebrate fauna of four intermittent Dinaric karst rivers in Croatia, we confirmed or recorded new distribution data and ecological features for several mayfly species rare in Croatian freshwater habitats: Nigrobaetis niger (Linnaeus, 1761), Procloeon pennulatum (Eaton, 1870) and Paraleptophlebia werneri Ulmer, 1920. To our knowledge, this is the first record of N. niger in intermittent lotic habitats. We discuss their substrate preferences in the studied habitats as well as their relationships with measured physico-chemical water parameters. The newly obtained results confirm that our knowledge about Croatian mayfly fauna and species ecological requirements in intermittent Mediterranean rivers is still incomplete and is increasing with systematic studies.

Biomonitoring and Water Quality Evaluation of River Beas in Mid Himalayan Zone, India

The present investigation was carried out on the Beas River, a major tributary of the Indus riverine system in the Mid Himalayan zone, to evaluate the physico-chemical and microbiological parameters during different seasons. For this, based on altitudinal differences, four observation sites were selected: S1 - Manali (urban land), S2 - Takoli (agricultural land), S3 - Mandi town (urban land) and S4 - Kunn Ka Tarr (forest land), located in the Kullu and Mandi districts of Himachal Pradesh. Lotic ecosystems can undergo rapid changes in their hydrology. Hence, biomonitoring using EPT index (Ephemeroptera, Plecoptera and Trichoptera) was also carried out at every station. Furthermore, temporal biological components (macroinvertebrates seasonal analysis) were added to the information acquired by traditional physico-chemical analysis. Macroinvertebrates are sensitive organisms and can act as bioindicators of water quality. The physico-chemical parameters analyzed in the study area were water temperature, pH, turbidity, total alkalinity, TDS, total hardness, chloride, dissolved oxygen, biological oxygen demand, chemical oxygen demand, and total coliforms. Species diversity indices such as Simpson, Shannon and Wiener, and Margalef’s diversity index of macroinvertebrates were calculated for all the monitoring sites on the river. There was no homogeneity observed among the stations, and it was concluded that every station had different trends due to different geographic location, altitude, land use in catchment, and most importantly nature of anthropogenic interference. The study also revealed that anthropogenic interferences not only changed the physico-chemical parameters of the river but also disturbed the macroinvertebrate fauna. The EPT index was low at stations (S1 and S3) where anthropogenic impact was relatively high.

Assessing the impact of artificial summer drainage on the benthic macroinvertebrates in a freshwater wetland in northeast Italy

Valle Mandriole is one of the two last remaining freshwater wetlands in the coastal area of Ravenna (NE Italy). In 2011, a management technique that involves the complete drainage of the southern portion of Valle Mandriole during summer has been undertaken. In the present study, the effects of this artificial drying on the benthic macroinvertebrate fauna were assessed using a beyond before-after-control-impact (beyond BACI) sampling design. Macroinvertebrates dwelling on macrophytes and in bare sediments were sampled in the impact location and in four control locations, two times before and two times after the drying period. Simultaneously, water samples were collected to monitor chemical properties potentially affecting the studied organisms. Biological and chemical data were analysed by multivariate statistical methods. The statistical analysis did not detect any significant effect of the management action on the benthic macroinvertebrates or on the water chemical and physical properties. This contrasts with some previous results, suggesting that the effects of a management strategy based on draining completely dry and then reflooding a wetland area are site specific. However, it is necessary to consider that the present study does have some limitations, in particular, the differences between impact and control locations and the timing of the sampling. The highest biodiversity was observed in one small and isolated control location; this highlights how maintaining, protecting, restoring and even creating small ponds may play an important role in biodiversity conservation.

Effects of application of copper-based fungicides in cocoa plantations on the abundance and diversity of macroinvertebrates in adjacent rivers in Southwestern Nigeria

This study investigated the relationship between the levels of fungicide pollution and the abundance and diversity of macroinvertebrate fauna in three river systems: Aponmu, Oruwo, and Owena in south-western Nigeria, which are in close proximity to cocoa plantations. For each river, three sites were selected for the collection of water and sediment samples from April to July, 2018. Prior to sample collection, the physicochemical parameters (electrical conductivity, total dissolved solutes, pH, temperature, and dissolved oxygen) were determined. Also, aquatic macroinvertebrates were collected, and were identified to generic level, where possible. The levels of copper and sulphate in the samples were determined following standard procedures. The range of mean values for the physicochemical parameters were: 0.07-0.20 mS/cm, 60.00 – 154.00 ppm, 24.60 – 28.13 °C, 6.97 – 7.43, and 0.87 – 2.87 mg/L for electrical conductivity, total dissolved solutes, temperature, pH, and dissolved oxygen respectively. The range of mean values for copper and sulphate in sediment samples were 30.58 – 56.63 mg/Kg and 787.12 – 978.33 mg/Kg respectively while those for the water samples were 2.86 – 6.93 mg/L and 476.6 – 685.58 mg/L respectively. A total of nineteen (19) macroinvertebrate genera comprising Insecta (14), Gastropoda (3), Crustacea (1), and Bivalvia (1) were recorded. Taxa richness and species diversity were higher in river Owena in comparison to rivers Aponmu and Oruwo. The high abundance of the taxa: Potamididae, Gerridae, Notonectidae, Libellulidae, and Platycnemididae in the sampled rivers notwithstanding the pollution levels is an indication that these taxa are capable of thriving in polluted aquatic systems.
 Keywords: Aquatic pollution; Copper-based fungicides; Black pod disease; Macroinvertebrates; Diversityindices

Environmental Drivers of Macroinvertebrate Assemblages within Peat Pool Habitat-Implication for Bioassessment

Macroinvertebrates are a crucial component of wetland trophic webs. Many taxa are used as bioindicators of ecosystem change. However, relationships between macroinvertebrates and the environmental factors in peat pool habitats are still not well recognized. The present study shows the results of long-term studies during the years 2010–2020, on the responses of macroinvertebrates to the changes of environmental variables in a peat pool habitat formed as a result of peat exploitation on continental raised bog. The RDA analysis significantly explained 87.3% of the variance in macroinvertebrates abundances. Assemblages of most taxa (Anisoptera, Chironomidae, Ceratopogonidae, Coleoptera, Hydrachnidia and Tabanidae) showed a strong relationship with N-NO3 and pH. Moreover, densities of Chaoboridae larvae were explained by chlorophyll-a concentrations. Dominant taxon, Chironomidae, constituted from 48% to 87% of total faunal density. The highest proportions showed larvae of Psectrocladius sp. (gr. sordidellus) and Chironomus sp. Changes in the composition of macroinvertebrate fauna over a period of 10 years reflect the eutrophication process of the peat pool and deterioration of habitat conditions.

The Macroinvertebrate Fauna of Nantucket's Perennial and Ephemeral Streams

Aquatic macroinvertebrate sampling in Nantucket streams produced a fauna typical of northeastern first-order low-gradient intermittent and perennial streams. Most taxa appear to be stream-specific, and as such would be particularly susceptible to stream disturbances. Abundance is low overall, with a few exceptions. Stream chemistry measurements fall within expected ranges for developed areas. Dissolved oxygen level, discharge and flow regime may be limiting factors in most of the streams.

Marine invertebrates associated with rhodoliths/maërl beds from northeast Brazil (State of Paraíba).

BackgroundThis study investigates the marine macroinvertebrate fauna of rhodolith beds (non-geniculated red corallinaceaous algae) in northeast Brazilian. A total of 57 species were identified, belonging to six phyla (Platyhelminthes, Annelida, Sipuncula, Mollusca, Arthropoda and Echinodermata), of which 50 are considered here as new records for the Paraíba State. Annelids (Class Polychaeta) were the most representative taxa in Miramar and Seixas Beaches, while molluscs were dominant in Maceió Beach.New informationThis is the first study that includes an identification key, diagnostic features and distribution patterns worldwide and local (including new records) of the marine invertebrate fauna associated with rhodolith beds in northeast Brazil (State of Paraíba). Sampling events were performed in 2018, at low tide in the intertidal to shallow subtidal zones (1.5 and 4.0 m depth), in Miramar, Seixas and Maceió Beaches. A total of 17 species were found for the first time on Seixas Beach, as well as all identified species for Miramar and Maceió. This study tries to contribute to the knowledge of marine invertebrates in northeast Brazilian shallow habitats, providing a baseline for future environmental studies.

Combining citizen science with spatial analysis at local and biogeographical scales for the conservation of a large-size endemic invertebrate in temperate forests

The ecology of leeches worldwide has been scarcely studied, with the ecology of Neotropical leeches remaining highly unknown. Americobdella valdiviana, an endemic, carnivorous, and giant leech that inhabits the Valdivian evergreen forest in southern Chile, an ecosystem that has experienced an increase in its net loss from 3.6% to 12% in the last decades due to various human activities. Here, we combined citizen science with species distribution models (SDM) to analyze (i) the effect of habitat variables with the abundance A. valdiviana, (ii) the distribution range, (iii) the habitat loss and fragmentation of A. valdiviana, and (iv) their conservation status. First, we asked each user or scientist for the observed relative abundance and a series of environmental variables, which were then correlated by using Generalized Linear Models. Then, distribution ranges were estimated using SDM, which was combined with multiannual forest cover maps to identify habitat loss and fragmentation between 2000 and 2018. Finally, we used IUCN criteria to evaluate the conservation status of this species. Abundance was related mainly to the canopy coverage, while suitability was positively associated to temperature seasonality and canopy cover. Suitability was higher in forests with levels of primary productivity. We found that the north and center zones of the species range experienced high habitat loss and fragmentation. Under IUCN Red List criteria, we qualified this species as endangered. Our results support that the combination of citizen science, SDM, and spatial analysis at local and biogeographical scales can inform conservation actions of poorly known and threatened macroinvertebrate fauna.

Investigation of environmental and land use impacts in forested permafrost headwaters of the Selenga-Baikal river system, Mongolia - Effects on discharge, water quality and macroinvertebrate diversity

Headwater streams play a major role for provision of ecosystem services, e.g. drinking water. We investigated a high-altitude headwater catchment of the Kharaa River (including 41 1st-order rivers) to understand the impact of land cover (especially forest cover), environment and human usage on runoff, chemical water quality and macroinvertebrate fauna in a river basin under discontinuous permafrost conditions in an arid, sparsely populated region of Mongolia. To verify our hypotheses that different landuses and environmental impacts in permafrost headwaters influence water quality, we investigated 105 sampling sites, 37 of them at intermittent stream sections without water flow. Discharge was positively impacted by land cover types steppe, grassland and forest and negatively by shrubland, forest burnt by wild fires (indicating a reduction of permafrost) and slope. Water quality was affected by altitude, longitude and latitude, shrub growth and water temperature. Shannon diversity of macroinvertebrates was driven by water temperature, iron content of the water, flow velocity, and subbasin size (adjusted R2 = 0.54). Sample plots clustered in three groups that differed in water chemistry, macroinvertebrate diversity, species composition and bio-indicators. Our study confirms that steppes and grasslands have a higher contribution to runoff than forests, forest cover has a positive impact on water quality, and diversity of macroinvertebrates is higher in sites with less nutrients and pollutants. The excellent ecological status of the upper reaches of the Kharaa is severely threatened by forest fires and human-induced climate change and urgently needs to be conserved.

Physicochemical Properties as Driver of Odonata Diversity in Oil Palm Waterways

Large-scale oil palm agriculture has caused deforestation in the tropics, but also degrades stream water quality and reduces aquatic biodiversity. Though the outcomes of industrial-scale oil palm plantations for biodiversity have been explored extensively, the consequences of small-scale oil palm agriculture for freshwater macroinvertebrate fauna are poorly understood. Here, we explored the impacts of small-scale oil palm agriculture on aerial adult Odonata (the dragonflies and damselflies), which, due to their inherent sensitivity to habitat degradation, represent useful indicators of wider ecosystem health. We surveyed riparian corridors of man-made waterways in natural habitats converted into agricultural lands in both peat swamp and mangrove forest, comprising a total of 60 sampling units across a region of Peninsular Malaysia where such small-scale agricultural practices are widespread. We hypothesized that physicochemical water quality of oil palm waterways together with riparian vegetation influence Odonata species richness and composition. Our results revealed that Odonata species richness increased with dissolved oxygen, water temperature and vegetation cover, but decreased with water level, pH, and total dissolved solids. Species composition was influenced by both dissolved oxygen and pH. The present study provides valuable insights into the effects of small-scale oil palm agriculture for water quality of associated aquatic habitats, and subsequent responses of adult Odonata. Therefore, smallholders should reduce the use of chemical pesticides and fertilizers to improve the conservation value of oil palm waterways for both Odonata and aquatic fauna more generally, in order to be certified as biodiversity-friendly agriculture.

Forests protect aquatic communities from detrimental impact by volcanic deposits in the tropical Andes (Ecuador)

Volcanic activity impacts ecosystems sometimes with multiple, complex and long-lasting consequences, including volcanic tephra (airborne material) causing widespread disruptions. We study the effects of tephra deposition around two tropical lakes of Ecuador using a multi-proxy analysis of lake sediment archives spanning the last 2000 years. We present the dynamics of terrestrial vegetation (pollen), aquatic macroinvertebrate fauna (chironomids) and organic matter (stable isotopes) in: (i) a high elevation, stream-connected, open alpine grassland (Andean páramo) and (ii) a mid-elevation, stream-isolated, pre-montane forest. Páramo vegetation showed a slight increase in herbs and quick recovery after the tephra deposition; however, the aquatic community suffered a regime shift not reversed today c. 1500 years after the event. In the pre-montane location, the canopy opened up following tephra deposition, and it took c. 150 years to return to pre-impact levels. At the forested site, no major changes in the aquatic fauna were observed related to the tephra deposition. We hypothesise that the forest acted as a protective barrier preventing a large fallout of ash into the aquatic system. Forest not only acted as a buffer for ash falling into the water from the air, but also prevented landslides of tephra by enhancing soil stability, contrary to what was observed in the open system. We demonstrate the protective ecosystem service that forests play in sustaining ecological resilience and water quality facing natural (volcanic) disturbance. The ongoing deforestation of tropical regions therefore might increase the vulnerability of aquatic ecosystems, threatening the water quality for ecosystems and human populations.

Determination of Benthic Macroinvertebrate Fauna and Some Physicochemical Properties of Balaban Lake (Menderes- Izmir)

In this study, we aimed to identify the benthic macroinvertebrate fauna and some physicochemical characteristics of Balaban Lake located in Menderes, Izmir. For this, benthic macroinvertebrate and water samples were taken from 5 stations of the lake from October 2019 to August 2020. As a result, a total of 25 taxa were identified and were classified as Annelida (Oligochaeta and Hirudinea), Mollusca (Bivalvia and Gastropoda), Crustacea and other Insecta (Trichoptera, Coleoptera and Diptera). The sampling stations were clustered by using the Bray-Curtis UPGMA analysis in terms of the distribution of the benthic macroinvertebrates. As a result of the UPGMA analysis, the 2nd and 3rd stations (88%) were the most similar to each other. The second most similar stations to each other were determined as the 1st and 4th stations (75%). This situation can be explained by the bottom structure (rich vegetation) of these stations. According to Pearson Correlation, there is a strong positive correlation (p<0.01) of TU, EC, TDS and TP with Nais communis, while there is strong positive correlation (p<0.05) of TU, EC and TDS with Nais elinguis. On the other hand, there is a strong negative correlation (p<0.01) of TU, pH, EC, TDS and TP with Gammarus sp. This study is the first study for determining Balaban Lake benthic fauna. That’s why all the taxa diagnosed in the stream has been recorded for the first time. 

Seasonal water‐level fluctuations and changes in macro‐benthic community structure in tropical reservoirs: A Sri Lankan case study

AbstractSeasonal water‐level fluctuations (WLFs) in reservoirs influence ecological processes, in turn affecting their benthic macroinvertebrate communities. The present study was carried out in 10 irrigation reservoirs of Sri Lanka to investigate the effects of seasonal WLFs on the benthic macroinvertebrate fauna. The study period was divided into two distinct phases: the drained period and the inundated period. Benthic macroinvertebrates were sampled during both periods and enumerated. Air temperature and soil quality parameters were also measured simultaneously, and hydrological data related to the Kala Oya River basin were obtained from irrigation authorities. Data analysis using non‐metric multi‐dimensional scaling revealed two distinct reservoir groups, namely, Hydrological Stress Group 1 (HSG1) and Hydrological Stress Group 2 (HSG2). A low hydrological residence time and low relative reservoir level fluctuations (RRLF) characterized HSG1, with the opposite describing HSG2. Temporal variations of macrobenthos indicated a high taxa richness and diversity in HSG1 reservoirs during the drained period, with scrapers and collector‐gatherers being the dominant functional feeding groups. Reservoirs in the lower river basin (HSG1) exhibited a high taxa richness and diversity. During the inundated periods, insect taxa colonized, particularly, chironomids and ephemeropterans. Molluscan taxa were prominent during the drained periods. These observations highlight the influence of seasonal fluctuations of reservoir water levels on benthic macroinvertebrates. Benthic macroinvertebrate communities in reservoirs were significantly influenced by the RRLF, manifesting the importance of hydrological regimes in reservoirs to develop macroinvertebrate metrics for water‐quality monitoring.

Community metabarcoding uncovers vast diversity and a lack of barcode references for aquatic invertebrates in Carpathian spring fens

Recent studies on diversity of stream amphipods proposed that the Western Carpathians have served as an important glacial refugium of freshwater fauna. If this scenario is true, a considerably high molecular diversity can be expected in this biogeographic region also for other taxa. In our project, we aimed to uncover and characterize molecular diversity of benthic macroinvertebrate fauna of spring fens, a well studied and hence convenient model community. Using a DNA metabarcoding approach, we sequenced a fragment of the COI gene of pooled spring fen invertebrate communities from 21 localities in the Western Carpathians. The preliminary analysis of the sequences revealed a substantially higher amount of operational taxonomic units (OTUs), when compared to the number of taxa identified in the same spring fens based on morphological characters. The lack of reference sequences in public databases (Barcoding of Life Database, GenBank) for the majority of the detected OTUs indicates that the Western Carpathian region is not yet sufficiently covered by barcoding efforts, and suggests that there indeed may be a considerable unrecognized diversity of macrozoobenthos. However, most newly uncovered diversity is concentrated in a few taxa such as the dipteran families Tabanidae and Ceratopogonidae, annelid species (complexes) Eiseniella tetraedra and Helobdella stagnalis or the amphipod genus Gammarus. In the future, these findings will be the basis for several levels of research: detailed investigation of seemingly hyperdiverse taxa (phylogeography, phylogeny, reference coverage) and comparison of overall molecular diversity of these communities in the Western Carpathians and neighbouring Bohemian Massif, a region where we expect much lower diversity due to different biogeographic history.

Crab Diets Differ Between Adjacent Estuaries and Habitats Within a Sheltered Marine Embayment

Portunid crabs contribute to significant commercial and recreational fisheries globally and are commonly fished in estuaries and/or marine embayments, which are amongst the most degraded of all aquatic ecosystems. Portunus armatus were collected seasonally between April and February from five locations across three systems in temperate south-western Australia. The dietary composition of crabs was quantified and compared between two estuaries (Peel-Harvey and Swan-Canning) and a sheltered marine embayment (Cockburn Sound) containing three distinct habitats: shallow seagrass, shallow sand and deep sand. Overall, crabs ingested large volumes of bivalves (both live organisms and dead shell), polychaetes, crustaceans (e.g., amphipods, small decapods), and smaller volumes of teleosts, echinoderms and plant material (seagrass, algae). Analysis of Similarities showed that dietary composition varied significantly among the five locations (two estuaries and three habitats within Cockburn Sound) and seasons, with greater location than seasonal differences in the two estuaries. Diets were most distinct in the Cockburn Sound seagrass due to greater volumes of decapods and teleosts and smaller volumes of bivalve shell consumed in this habitat. Crabs from both estuaries consumed greater quantities of bivalves than those from Cockburn Sound. Seasonal differences in both estuaries were greatest between summer and winter, with a more diverse range of prey and large quantities of bivalves ingested in summer, whereas small bivalves and bivalve shell in the Peel-Harvey and polychaetes and other crustaceans in the Swan-Canning, were consumed in greater quantities in winter. The summer diet in the Peel-Harvey Estuary in the current study was compared to that 20 years previous and with documented change in the benthic macroinvertebrate fauna. Currently, crabs consume smaller volumes of high-calorie prey, i.e., polychaetes, small bivalves and teleosts, and instead ingest greater proportions of calcareous material than previously. This marked shift in dietary composition parallels changes in benthic macroinvertebrates in the Peel-Harvey Estuary. Overall, prey availability appears to be the major factor influencing the spatial and temporal differences in P. armatus diets in these three coastal systems.

Habitat preference and diversification rates in a speciose lineage of diving beetles

The long-term geological stability of aquatic habitats has been demonstrated to be a determinant in the evolution of macroinvertebrate fauna, with species in running (lotic) waters having lower dispersal abilities, smaller ranges and higher gene flow between populations than species in standing (lentic) environments. Lotic species have been hypothesized to be more specialised, but the diversification dynamics of both habitat types have not been studied in detail. Using a speciose lineage of water beetles we test here whether diversification rates are related to the habitat preference of the species and its consequences on turnover, which we expect to be higher for lotic taxa. Moreover, we tested whether life in lotic environments is acting as an evolutionary dead-end as it is considered an ecological specialisation. We built a comprehensive molecular phylogeny with 473 terminals representing 421 of the 689 known species of the tribe Hydroporini (Coleoptera, Dytiscidae), using a combination of sequences from four mitochondrial and two nuclear genes plus 69 mitogenomes obtained with NGS. We found a general pattern of gradual acceleration of diversification rate with time, with 2–3 significant diversification shifts. However, habitat is not the main factor driving diversification in Hydroporini based on SecSSE analyses. The most recent common ancestor of Hydroporini was reconstructed as a lotic species, with multiple shifts to lentic environments. Most frequent transitions were estimated from lentic and lotic habitats to the category “both”, followed by transitions from lotic to lentic and lentic to lotic respectively, although with very similar rates. Contrary to expectations, we found little evidence for differences in diversification dynamics between habitats, with lotic environments clearly not acting as evolutionary dead-ends in Hydroporini.

The diversity of marine invertebrate macrofauna in selected rocky intertidal zones of Matara, Sri Lanka

The present study was conducted in intertidal rocky shores at Wellamadama and Kamburugamuwa of Matara district from June to November 2018. A line transect method was employed perpendicular to the shore and randomly placed quadrats were used to identify and quantify the species. Collectively 34 species of intertidal macroinvertebrate fauna were identified. Shanon-Weiner index, Menhinick’s index, and Pielou’s index for Wellamadama were 1.8271, 0.5612, and 0.7620 respectively, while those in Kamburugamuwa were 1.9281, 0.4307, and 0.7517. Higher species diversity was recorded at the rocky shores of Kamburugamuwa, while higher species richness and evenness at Wellamadama rocky shores. The Jaccard similarity index indicates a low similarity (<50%) between two study rocky shores. Clypidina notata, Cellana rota, and Patelloida striata were the dominant species in the low tide zone. Highly abundant species in mid tidal zone at Wellamadama was Nodilittorina quadricincta, while that of in mid-tide zone at Kamburugamuwa was Chiton sp. Periwinkle snails were dominating the high tide zone of both study rocky shores of which Nodilittorina trochoides dominated at Wellamadama and Littoraria undulata dominated at Kamburugamuwa. The study indicates that community assemblages in intertidal rocky shores vary spatially and comprehensive studies are essential to investigate the controlling factors.