Volume 17, Issue 1 (2022)
published March 2022
Contents | |
Research articles |
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Karsten Reise, Rune Michaelis and Nataliya Rybalka
Invading grass-like alga transforms rippled sand bars into bumpy muddy flats: arrival of a game changer in the Wadden Sea?
(pp 1–20)
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In the wake of biological globalization, translocated species of high bio-engineering capacity increasingly change bottom topography of sedimentary coasts.
A Vaucheria-taxon (Xanthophyceae) of unknown origin is spreading at the transition between intertidal and subtidal zones, while resident Vaucheria-species
are confined to the upper shore in the Wadden Sea (European Atlantic). Near the island of Sylt, dense turfs of green filaments rapidly expanded over an area of 180 ha
within 3 years. The unicellular filaments reach about 5 cm out of and 5 cm into the sediment. Felted rhizoids provide firm anchorage. Dry phytomass
(up to 208 g m-2) was similar to that of intertidal seagrass beds. Residual filaments overwinter in the sediment and give rise to renewed growth
in late spring. In addition, oospores germinate. Fine particles are trapped by the turf during summer, generating laminated cohesive mud. Muddy hummocks arise
up to 20 cm above ambient sand flats, alternating with troughs but gradually merge into coherent and pertinacious plateaus of mud. This shift in bottom topography
and sediment composition may potentially change the mud balance of tidal basins, and the capacity of tidal flats in catching up with accelerating sea-level rise. |
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Maxim V. Vinarski, Olga V. Aksenova, Ivan N. Bolotov, Alexander V. Kondakov, Irina S. Khrebtova, Mikhail Yu. Gofarov, Michael Schindler and Michael Zuykov
A new alien snail Ampullaceana balthica for the Canadian fauna, with an overview of Transatlantic malacofaunal exchange in the Anthropocene
(pp 21–35)
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A survey of the exchange of freshwater gastropods mollusks between Europe and North America is provided. Several dozen
species of snails migrated, during the last two centuries, in either direction across North Atlantic and this process
is ongoing. The intensity of the faunal exchange is unequal since much more snail species have dispersed from North America
to Europe than in the opposite direction. Two cases of “failed” invasions of North American lymnaeid snails to Europe
are discussed. A species of pulmonate snails, Ampullaceana balthica (Linnaeus, 1758), is reported here as new
for the malacofauna of Canada (and for the whole North America). This snail of European origin was found in June 2019
in a small lake in the vicinities of Rimouski Town (Québec, Canada). The taxonomic identification of the mollusks was
confirmed by molecular analysis, with the studied specimens having two unique COI haplotypes, hitherto not found in Europe. |
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Summer Henricksen and Stephen M. Bollens
Abundance and growth of the invasive Asian clam, Corbicula fluminea, in the lower Columbia River, USA
(pp 36–56)
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The Asian clam, Corbicula fluminea, is a broadly distributed and abundant invasive species, yet many aspects of its biology are not well understood.
Based on previous research by other investigators, we hypothesized that abundance, population growth rate, and individual growth rate of C. fluminea
would increase with temperature, chlorophyll-a, and dissolved oxygen. We sampled C. fluminea at two sites in the lower Columbia River (CR), USA.
Modal progression analyses indicated a life span of 2–3 years. A generalized linear mixed model (GLMM) predicting the abundance of C. fluminea indicated
a significant negative association with chlorophyll-a concentration, whereas a GLMM predicting the population growth rate of C. fluminea indicated
a significant positive association with dissolved oxygen. The GLMM predicting the individual growth rate of C. fluminea indicated the individual growth rate
was not significantly related to any individual environmental variable. Overall, these results emphasize that the biology of C. fluminea in the CR is similar
in many regards to other populations studied in temperate regions globally, but that important spatial differences can occur between sites separated by 60 km within
the same river system. |
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Karine Gagnon, Heidi Herlevi, Jenny Wikström, Marie C. Nordström, Tiina Salo, Sonja Salovius-Laurén and Henna Rinne
Distribution and ecology of the recently introduced tanaidacean crustacean Sinelobus vanhaareni Bamber, 2014 in the northern Baltic Sea
(pp 57–71)
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The non-indigenous tanaidacean crustacean Sinelobus vanhaareni Bamber, 2014 was first found in northern Europe in 2006 and has since spread to the northern Baltic Sea.
Here, we surveyed the distribution of the species in different habitats in southwestern Finland, focusing on vegetated macroalgal and seagrass habitats
(i.e., Fucus vesiculosus beds and Zostera marina meadows). We also evaluated its potential impacts by synthesizing current knowledge on the traits and ecology
of the species, and identified knowledge gaps. We found that S. vanhaareni is now present throughout most of the southwestern Finnish coast, in a number of vegetated
and non-vegetated substrates down to 25 m depth. Furthermore, the presence of egg-brooding females in most areas also confirms that the population is self-sustaining.
The species is especially abundant in shallow macroalgal belts and eelgrass meadows, which are critical habitats for biodiversity, ecosystem functioning, and ecosystem service
provisioning, highlighting the need to understand the effects of S. vanhaareni in these important ecosystems. Its presence on boat hulls and in marinas and harbours
suggests that recreational boating may be a major spread vector, while drifting macroalgal fragments may also contribute to regional spread. At this stage of invasion,
we found high overlap in epifaunal community composition in sites where S. vanhaareni was present and sites where it was absent. Based on the functional traits of
S. vanhaareni and closely related species, we infer that it is likely part of the detritus-based pathway in benthic food webs. However, additional sampling and experiments
are necessary to determine the true extent of its distribution and to quantify trophic links (through stable isotope analysis, gut content analysis, and experimental trials)
to fully understand its effects on communities and trophic networks in the northern Baltic Sea. |
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Fabian Herder, Jan Möhring, Jana M. Flury, llham Vemandra Utama, Letha Wantania, Daisy Wowor, Farnis B. Boneka, Björn Stelbrink, Leon Hilgers, Julia Schwarzer and Jobst Pfaender
More non-native fish species than natives, and an invasion of Malawi cichlids, in ancient Lake Poso, Sulawesi, Indonesia
(pp 72–91)
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Ancient Lake Poso in Central Sulawesi, Indonesia, is among the deepest lakes in Asia, and hosts a largely endemic fauna of fishes, crustaceans, and molluscs.
Introduction of non-native fish species started at least a century ago to foster local fish production. Recent fieldwork suggests that introduction of non-native
fishes is ongoing, including species that originate from the ornamental pet trade. These include the hybridogenic ornamental “flowerhorn” cichlid, a fish that
spread rapidly in Sulawesi’s Malili Lakes, and the “golden cichlid”, Melanochromis auratus from African Lake Malawi. This popular aquarium species colonized
Lake Poso even more rapidly than the flowerhorn, and is omnipresent at benthic habitats across most of the lake. Here, we list records of 17 non-native fish species
from Lake Poso, present the first assessment of golden cichlid stomach contents outside of their native habitat, report the occurrences of non-native crustaceans,
molluscs and plants, and discuss potential impacts on the native fauna and ecosystem. Most of the non-native species have established substantial populations,
and it appears very plausible that the non-native fauna affects endemics. This is supported by the finding that golden cichlid stomachs contained a broad spectrum
of items, including fish, their scales, fins, eggs and larvae, and various invertebrates. We conclude that non-native species introduction poses a substantial
and increasing threat to the Lake Poso fauna, a major hotspot of aquatic biodiversity in the Wallacea region. |
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Hui Wei, Fei Liu, Lorenzo Vilizzi, Louisa E. Wood, Yinchang Hu and Gordon H. Copp
Environmental related variation in growth and life-history traits of non-native sailfin catfishes (Pterygoplichthys spp.) across river basins of South China
(pp 92–109)
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Plasticity in growth and life-history traits is an important attribute of non-native (NN) fishes, facilitating their adaptation to novel environments.
Few studies have investigated geographical variations in multiple biological traits and the factors affecting the variations. In this study, variations
in multiple biological traits of NN sailfin catfishes Pterygoplichthys spp. were investigated in the main river basins of the Guangdong and Hainan
provinces of South China. The impacts of environmental factors on the biological traits were analysed using general linear modeling and an information-theoretic
approach. Among-basin differences in population growth was observed, with richness of competitor fishes negatively affecting growth, maturity and
reproductive traits – this suggests biotic resistance was mediated by competition with native fishes. These traits were positively affected by total phosphorus
concentration, which is indicative of bottom-up effects, mediated by inorganic nutrients, potentially playing an important role in the invasion success
of NN fish. In population level, a bet-hedging strategy was observed in sailfin catfishes under unfavourable environment conditions (e.g. Nangdujiang),
whereas a “master-of-some” strategy was found under favourable conditions (e.g. Pearl River Delta and Western Basin). The results suggested that plasticity
in multiple biological traits of sailfin catfishes is an important strategy to overcome changing environmental conditions in different rivers,
and habitat-specific variations across river basins would reflect trade-offs amongst traits at the population level. Therefore, habitat-specific management
measures, adapted to the invaded ecosystem’s features and the life-history strategy of the NN species, could provide an effective means to control invasive
species. |
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Beata Więcaszek, Jarosław Dąbrowski, Remigiusz Panicz, Sławomir Keszka, Angelika Linowska and Adam Brysiewicz
Taxonomic studies of Piaractus brachypomus (Cuvier, 1818) (Serrasalmidae): a non-native species collected from Polish water bodies and laboratory culture
(pp 110–135)
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Piaractus brachypomus is highly valued as an aquaculture and ornamental fish species. However, it is frequently considered
as a non-native or invasive species. In Polish waters P. brachypomus is an incidental non-native species, most likely
released by aquarists, and it is unable to overwinter or reproduce. Outside its native distributional range, this species has been
recorded nearly world-wide. In regions where exist it is often confused with other species such as Piaractus mesopotamicus
and Piaractus orinoquensis, possibly with Colossoma macropomum and their hybrids, and Pygocentrus nattereri.
In this study, we provide a detailed taxonomic description and the most useful discriminative features for the species, of five
specimens of P. brachypomus caught in water bodies in northwestern Poland (in 2002–2010), and a sample of 11 specimens
obtained from laboratory culture (2012–2019) that originated from South America. The examinations included describing metric
and meristic characters, the neurocranium structure, the dentition formula, parasite fauna, and species identification based
on a mitochondrial COI sequence. The phylogenetic tree inferred using maximum likelihood showed that pirapitinga samples were
nested within the Amazon Basin clade of P. brachypomus. This is the first molecular study in Europe and first detailed
morphometric study (including the neurocranium) of this species from a non-native area of its distribution. Characters such
as dentition can be used to discriminate among the genera Colossoma, Piaractus and Pygocentrus, while meristic
characters such as lateral line scale counts, numbers of scale rows above and below the lateral line, pectoral and pelvic fin rays
counts, and ventral-keel spine counts can be used to discriminate among species within the genus Piaractus. Nevertheless,
morphometric characters do not seem to be an appropriate tool to distinguish closely related species in the genus Piaractus. |
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