Round gobies in the third dimension - use of vertical walls as habitat enables vector contact in a bottom-dwelling invasive fish

Sessile invasive species often efficiently exploit anthropogenic structures, such as harbour walls and pontoons, which can lead to increased vector contact (i.e. contact with boats), and therefore spread rate. The round goby (Neogobius melanostomus) is a bottom-dwelling invasive fish species which was never documented on boats or habitats near the water surface. In this study, we wanted to find out if this fish makes use boat hulls and other vertical anthropogenic structures, which could act as invasion beachheads. We inspected boats close to harbour walls in the river Rhine in Basel, Switzerland, to search for gobies on them and documented the position of the boat and the ways the gobies could have reached the hull. We observed round goby presence on three different boats, with up to 28 goby sightings on one boat hull in the course of 45 minutes. Additionally, we recorded gobies on walls between one and five meters above the ground. Based on these observations, we investigated the behaviour of round gobies using vertical walls as habitat and compared the observed behaviours to those exhibited by gobies on the bottom. Gobies used the habitat along a wall in a generally similar fashion to the habitat on the bottom. However, they sat still for less time and moved more on walls than on the bottom, while feeding activity was similar in both habitats. The results raise questions about the drivers for using vertical structures as habitat in the usually bottom-dwelling round gobies and the plasticity of this behaviour. Our study documents round gobies in direct contact with boats for the first time. Potentially, gobies could find hiding places or suitable structures to nest on boats. This study therefore provides support for the theory that boat hulls are potential vectors for the translocation of round gobies. Our observations should lead to an increased awareness about fish and their eggs on boat hulls and stimulate efforts to implement measures like the check-clean-dry routine for commercial as well as private boats

Sound production in male and female corkwing wrasses and its relation to visual behaviour

In fish, social interactions are commonly accompanied by acoustic signalling. Males have been found to produce sounds in a large range of species, but female sounds have received considerably less attention. But even in males, there remain significant taxonomical gaps, e.g. in one of the largest fish families, the wrasses. Here, we investigate sound production in territorial males and females of the corkwing wrasse in a field study in Norway. We complemented an in-depth analysis of the visual and acoustic behavioural repertoire of territorial males by descriptions of female behaviours. Males as well as females produced sounds in courtship and agonistic contexts. We recorded four types of sounds and found significant differences between male and female sound properties. We hereby provide one of the first descriptions of sound production in wrasses and, to our knowledge, the first one to also investigate female sound production. Our study shows that wrasses are an underappreciated family when it comes to sound production. With a repertoire of four different calls, corkwing wrasses are remarkably versatile among fishes. Our results highlight the potential and importance of future research about sound communication in neglected taxa, and in both sexes.publishedVersio

Herbal mixtures in traditional medicine in Northern Peru

The investigation of plant mixtures used in traditional medicine in Northern Peru yielded a total of 974 herbal preparations used to treat 164 different afflictions. Psychosomatic disorders were, with almost 30% of all recipes applied, the most important afflictions treated. In most cases, healers used only one or two mixtures to treat an illness. However, up to 49 different preparations were used to treat the same disease. This indicates a high degree of experimentation. Altogether 330 plant species, representing almost 65% of the medicinal flora used in the region were applied in mixtures. The overwhelming number of plant mixtures contained 2-7 different plant species, although in the most extreme case 27 distinct species were included. The cluster analysis confirmed that mixtures used for applications like inflammations, infections and blood purification, as well as cough, cold, bronchitis or other respiratory disorders, or urinary infection and kidney problems had similar floristic compositions. Mixtures used for nervous system disorders, anxiety and heart problems often had a similar compositio

Ecological, behavioural and molecular aspects enabling invasive round goby translocation via boats

Aquatic invasive species are one of the biggest threats to biodiversity worldwide. Especially in freshwater ecosystems, the introduction of non-native species has led to many detrimental ecological and economic effects. Invasive fish belong to the taxa that exert the most severe impacts on aquatic ecosystems, and globally caused the decline or extinction of native species through predation or competition. Understanding and preventing ways of translocation is crucial to avoid further introductions of invasive fish. The round goby (Neogobius melanostomus) is one of the most notorious invasive fish species in European and North American waters. A commonly proposed way of translocation for round gobies is that they lay eggs on boat hulls, which can then be transported within or across water bodies. For example, translocation via recreational boats could help round gobies to spread into the ecologically and economically valuable lakes of Switzerland, which cannot be reached via ballast water transport or active dispersal. However, it is unclear how the bottom-dwelling round goby establishes contact with boats on the water surface. In this study, we investigate potential mechanisms of round goby translocation via recreational boats and derive measures to prevent it by determining which life stages act as propagules, how vector contact is established, and which mechanisms contribute to a successful translocation. A key behavioural aspect enabling egg deposition on boat hulls is vertical habitat use. Round gobies readily use vertical harbor walls as habitat and use them as beachheads to reach boat hulls, potentially enabling egg deposition there. While practical evidence for round goby eggs on boat hulls is still missing, high breeding frequencies in spawning traps close to the surface confirms that nesting there is a plausible option. Round gobies using vertical habitat are larger and more generalist than those using the bottom substrate during the reproductive season. This differential habitat use by a more competitive subset of the population could help to explain the successful translocation history of round gobies. Another aspect that helps round goby eggs to survive adverse conditions during overland transport is their desiccation tolerance of up to 48 hours. Molecular mechanisms including an enhanced response to oxidative stress, adjustment in protein metabolism and changes in developmental processes contribute to the survival of prolonged desiccation. The confirmed presence of a round goby larva inside a boat motor shows that there is a second possible mode of translocation via recreational boats. Round goby larvae drift in the water column at night, making their uptake via cooling water intake possible. A compilation of anecdotal reports of fish and other macrofauna inside of boat motor cooling systems from boating forums and the observation of regular presence of boats active after sunset confirms that this mode of translocation can accelerate in-water spread of invasive fish. Understanding translocation mechanisms of invasive species is crucial for the prevention of their spread. The studies included in this work demonstrate the different ways in which recreational boats can contribute to the introduction of invasive fish into new water bodies and reveal mechanisms that enable vector contact and survival of transport. The results elucidate novel aspects of why certain species are successful invaders and can improve future risk models. The translocation of eggs laid on boat hulls and larvae in cooling water systems can be mitigated by different measures like adjustment of mooring conditions, thorough cleaning of potential nest sites on boats, drying of boats over several days, or emptying and flushing cooling systems before every transport. Applied in management campaigns and communicated to relevant stakeholders, the proposed measures can therefore improve the biosecurity of un-invaded waters

Sound production in male and female corkwing wrasses and its relation to visual behaviour

In fish, social interactions are commonly accompanied by acoustic signalling. Males have been found to produce sounds in a large range of species, but female sounds have received considerably less attention. But even in males, there remain significant taxonomical gaps, e.g. in one of the largest fish families, the wrasses. Here, we investigate sound production in territorial males and females of the corkwing wrasse in a field study in Norway. We complemented an in-depth analysis of the visual and acoustic behavioural repertoire of territorial males by descriptions of female behaviours. Males as well as females produced sounds in courtship and agonistic contexts. We recorded four types of sounds and found significant differences between male and female sound properties. We hereby provide one of the first descriptions of sound production in wrasses and, to our knowledge, the first one to also investigate female sound production. Our study shows that wrasses are an underappreciated family when it comes to sound production. With a repertoire of four different calls, corkwing wrasses are remarkably versatile among fishes. Our results highlight the potential and importance of future research about sound communication in neglected taxa, and in both sexes

Sound production in male and female corkwing wrasses and its relation to visual behaviour

In fish, social interactions are commonly accompanied by acoustic signalling. Males have been found to produce sounds in a large range of species, but female sounds have received considerably less attention. But even in males, there remain significant taxonomical gaps, e.g. in one of the largest fish families, the wrasses. Here, we investigate sound production in territorial males and females of the corkwing wrasse in a field study in Norway. We complemented an in-depth analysis of the visual and acoustic behavioural repertoire of territorial males by descriptions of female behaviours. Males as well as females produced sounds in courtship and agonistic contexts. We recorded four types of sounds and found significant differences between male and female sound properties. We hereby provide one of the first descriptions of sound production in wrasses and, to our knowledge, the first one to also investigate female sound production. Our study shows that wrasses are an underappreciated family when it comes to sound production. With a repertoire of four different calls, corkwing wrasses are remarkably versatile among fishes. Our results highlight the potential and importance of future research about sound communication in neglected taxa, and in both sexes

Invasive goby larvae: first evidence as stowaways in small watercraft motors

Aquatic invasive species (AIS) are a major threat to aquatic ecosystems worldwide. Despite management efforts, human assisted dispersal continues to distribute AIS within and across waterbodies. An understudied translocation vector for AIS, especially for invasive fish, are the cooling systems of small watercraft motors. Here, we investigate the contents of boat motor cooling systems for the presence of invasive goby larvae in a collaboration with local boat owners. Because of the exclusively nocturnal drift activity of goby larvae, to collect samples we drove boats in the first hours after sunset. For an estimate of the translocation potential, we quantified drift density of goby larvae as well as boat traffic after sunset. We found a goby larva in a boat motor once in 30 boat drives of 1-2 hours duration each. Peak drift densities of goby larvae were 2.5 per 100 m3, which is comparable to previously reported data. Recreational boats were active after sunset throughout the reproductive season of invasive gobies and are therefore a realistic translocation vector for goby larvae. Additionally, evidence of fish and other animals inside boat motor cooling systems, gathered from online boating forums, demonstrates the potential of AIS transport in small watercraft. Translocation inside motors is especially likely for in-water transport of boats, which should be a management focus in interconnected aquatic systems