Fish Families Research Articles

Do Cormorants and Recreational Anglers Take Fish of the Same Species and Sizes?

The Great Cormorant Phalacrocorax carbo is a widespread piscivorous waterbird. The competition for resources between recreational anglers and Cormorants has been causing serious conflicts between sport fisheries and environmentalists. This study aimed to compare fish catches by Cormorants and by recreational anglers in the upper Elbe River in Central Europe (Czech Republic). Cormorant diet was studied using regurgitated pellets, and catches of anglers were obtained from annual angling reports. Altogether 1478 Cormorant pellets were collected from which 6903 fish were measured and identified to species level. A total of 93,413 fish caught by anglers were identified to species level. Cormorant diet consisted of 24 fish species in six fish families. Cormorants caught smaller-sized fish (median mass 90 g) compared to fish caught by anglers (median mass 1700 g). The majority of fish caught by Cormorants were under the minimum legal catchable size for anglers. Species of moderate interest to anglers (mainly Roach Rutilus rutilus) dominated in Cormorant diets while Common Carp Cyprinus carpio dominated in catches of anglers. In conclusion, the direct competition for fish between anglers and Cormorants appeared low. However, as Cormorants consumed small fish that serve as prey for piscivorous fish species and that could potentially grow into legally sized fish for angling purposes, this still allows for indirect competition between Cormorants and sport fisheries.

Assessment of conservations actions for the critically endangered spotted handfish (Brachionichthyidae), following curation of data collected by multiple investigators into a long-term time-series

Multi-decadal datasets for endangered species that track both populations and performance of management interventions are rare. One such dataset is for the critically endangered Spotted handfish, a species which has been used as a conservation model for the most endangered of the marine bony fish families the Brachionichthyidae. We assessed a 23-year, multi-site, time-series of population density surveys for the spotted handfish as well as a conservation intervention, the planting of ∼ 14,000 artificial spawning habitats (ASH). Data ownership spanned multiple Principal Investigators (PIs) and key data and covariates, such as monitoring and interventions, were often documented within personal files and difficult to access grey literature. We consolidated and curated these data, identifying gaps in the time-series and their causes and isolating confounding factors before we assessed population trends and the effectiveness of ASH planting. Both funding gaps and the 2020 Covid-19 lockdown produced breaks in the time-series. Breeding season observations mostly occurred in the early part of the dataset and there was also a change in method that needed to be considered when interpretating the time-series. There was an overall decline in fish observed between 1997 and 2019 but, at least since 2014, there has been stabilisation of the population. Local populations of spotted handfish can either be highly dynamic or relatively stable but population increases were linked to the long-running, conservation intervention of planting ASH. As local populations can be dynamic, the functional life span of the ASH is limited and threats to the species - chronic, stochastic and climate - are ongoing, spotted handfish may be a ‘conservation reliant’ species that require annual site-specific monitoring, insitu interventions and existu captive husbandry.

An Adaptable Flying Fish Robotic Model for Aero- and Hydrodynamic Experimentation.

Flying fishes (family Exocoetidae) are known for achieving multi-modal locomotion through air and water. Previous work on understanding this animal's aerodynamic and hydrodynamic nature has been based on observations, numerical simulations, or experiments on preserved dead fish, and has focused primarily on flying pectoral fins. The first half of this paper details the design and validation of a modular flying fish inspired robotic model organism (RMO). The second half delves into a parametric aerodynamic study of flying fish pelvic fins, which to date have not been studied in-depth. Using wind tunnel experiments at a Reynolds number of 30,000, we investigated the effect of the pelvic fin geometric parameters on aerodynamic efficiency and longitudinal stability. The pelvic fin parameters investigated in this study include the pelvic fin pitch angle and its location along the body. Results show that the aerodynamic efficiency is maximized for pelvic fins located directly behind the pectoral fins and is higher for more positive pitch angles. In contrast, pitching stability is neither achievable for positive pitching angles nor pelvic fins located directly below the pectoral fin. Thus, there is a clear a trade-off between stability and lift generation, and an optimal pelvic fin configuration depends on the flying fish locomotion stage, be it gliding, taxiing, or taking off. The results garnered from the RMO experiments are insightful for understanding the physics principles governing flying fish locomotion and designing flying fish inspired aerial-aquatic vehicles.

MAINTENANCE OF THE BUTTERFLYFISH Chaetodon striatus (PERCIFOMES: CHAETODONTIDAE) IN A RECIRCULATION SYSTEM

The hight extractivism of marine fish to supply the demand of the aquarium market has worried the researchers and, in this context,, the aquaculture consists of an alternative to the problem. The family Chaetodontidae represents one of the main families of ornamental marine fish and has not received enough attention on their cultivation research. Considering the absence of this information about the butterflyfish Chaetodon striatus, the present work had the objective of obtaining information about the species in captivity. The fishes were kept in tanks of 100, 200, 300 and 1,000 L, with 6 fishes in each tank, with 3 repetitions for each volume, totaling 72 individuals and were observed for 30 days, being offered living small invertebrates and frozen and fresh mussels for the feeding. Also, for the attempt of reproduction in captivity, two couples, collected directly from the sea, with the entry of only two adults in the trap at a time, were used. Each couple was acclimated in a 100 L tank and we observed their behaviors for 8 hours a day. There was no mortality in tanks of 300 and 1,000 L and, for feeding, small invertebrates and fresh mussels were well accepted. Some behaviors were observed, most of which were already described for chaetodontids. This is the first report of C. striatus in captivity and this contribution may provide subsidies for a future technologi­cal package.

Capture of a new for the basin of Peter the Great Bay (Japan Sea) fish species ayu <i> Plecoglossus altivelis </i> (Temminck & Schlegel, 1846) (Plecoglossidae)

For the first time, natural entry of ayu or sweetfish into the river of Peter the Great Bay basin (Japan Sea) and generally into the waters of Russian Federation is registered. This finding extends the list of fish species and families dwelling in the Russian waters.

BIODIVERSITY OF FISH FAMILY OSPHRONEMIDAE IN SWAMP WATERS IN BAGAN BILAH VILLAGE, DISTRICT OF PANAI TENGAH LABUHANBATU REGENCY

One of the swamp waters is located in Bagan Bilah Village, Panai Tengah District, Labuhanbatu Regency, North Sumatra Province. These swamp waters store a lot of fish diversity that has been used by the surrounding community. Among them are fish from the Osphronemidae family. This study aims to determine the biodiversity of fish of the Osphronemidae family in the swamp waters of Bagan Bilah Village. Fish sampling was carried out for 3 months, starting from October to December 2021. Fish are caught using traditional fishing gear called tangkol. The caught fish are collected, counted in number and then identified by species. The research data is calculated for its ecological index using the 2010 version of the Microsoft Excel application, then the data is displayed in tabular form. Based on the results of this study obtained 5 species of fish family Osphronemidae (Belontia hasselti, Betta imbellis, Trichogaster trichopterus, Trichopodus pectoralis, and Trichopsis vittatus). The Diversity Index (H') of Station 1 (0.78), Station 2 (0.76), and Station 3 (1.26). Uniformity Index (E) for Station 1 (0.43), Station 2 (0.42), and Station 3 (0.70). Dominance Index (C) for Station 1 (0.13), Station 2 (0.16), and Station 3 (0.28).

Genomic Survey and Microsatellite Marker Investigation of Patagonian Moray Cod (Muraenolepis orangiensis).

Simple SummaryPatagonian moray cod is known to inhabit the cold waters near Antarctica, and it belongs to the Muraenolepis genus. This genus has seven species, and five of them are recently reported. The Muraenolepis genus has similar morphological characters, and this is a limitation of taxonomical classification. In this study, a genome survey and microsatellite marker analysis were conducted to characterize the genome profile for classification. As a result, genomic data such as genome size and microsatellite motifs were obtained.The Muraenolepididae family of fishes, known as eel cods, inhabits continental slopes and shelves in the Southern Hemisphere. This family belongs to the Gadiformes order, which constitutes one of the most important commercial fish resources worldwide, but the classification of the fish species in this order is ambiguous because it is only based on the morphological and habitat characteristics of the fishes. Here, the genome of Patagonian moray cod was sequenced using the Illumina HiSeq platform, and screened for microsatellite motifs. The genome was predicted to be 748.97 Mb, with a heterozygosity rate of 0.768%, via K-mer analysis (K = 25). The genome assembly showed that the total size of scaffolds was 711.92 Mb and the N50 scaffold length was 1522 bp. Additionally, 4,447,517 microsatellite motifs were identified from the genome survey assembly, and the most abundant motif type was found to be AC/GT. In summary, these data may facilitate the identification of molecular markers in Patagonian moray cod, which would be a good basis for further whole-genome sequencing with long read sequencing technology and chromosome conformation capture technology, as well as population genetics.

Revealing the foraging movements and diet of the White-faced Storm Petrel Pelagodroma marina in the NE Atlantic

The White-faced Storm Petrel (WFSP) Pelagodroma marina has a widespread distribution, although virtually nothing is known about their feeding ecology and distributions at-sea. To describe their foraging areas, a total of 77 birds were equipped with 1 g-GPS loggers on Selvagem Grande, Madeira, Portugal (30° 09′ N, 15° 52′ W), during the 2018 and 2019 breeding seasons. We also assessed the diet of WFSP by analysing 17 faecal samples from chicks and 1 regurgitation from an adult using DNA metabarcoding techniques. Additionally, we collected body feathers from ten WFSP chicks to determine mercury concentration. WFSP fed mainly in deep oceanic waters, travelling up to 400 km from the colony, and did not concentrate in any well-defined, population-level foraging hotspots. Some individuals foraged along the edge of the shelf, near the African coast and the Canary Islands, especially during chick rearing. The duration of foraging trips and the total distance travelled, were, on average, 5.1 days and 723 km during the incubation period and 3.0 days and 578 km during chick rearing. The diet of WFSP was dominated by fish and cephalopods (crustacean prey were not detected), with Myctophidae (FO = 71%) representing the main fish family. WFSP often consume mesopelagic fish, in line with their preference for deep oceanic waters and with a small difference in at sea behavior (i.e., travel speed) between the diurnal and nocturnal period. The relatively high concentrations of mercury accumulated in body feathers of WFSP chicks (3.45 ± 1.44 mg kg−1 dry weight; range 1.68–6.01 mg kg−1) support the idea that WFSP raise their chicks mostly on mesopelagic prey from deep pelagic areas.

Dimorphic Fluorescence in the Pacific Spiny Lumpsucker

Joining the ranks of vertebrates that glow is the Pacific Spiny Lumpsucker, Eumicrotremus orbis, a subtidal species widely distributed across the North Pacific Ocean. Aside from their charismatic appearance, the Pacific Spiny Lumpsucker is known for its ventral suction disc that is used to stick to substrates amid changing currents and tides. Here we show that red lumpsuckers, which are usually male and a deep red color under broad-spectrum light, fluoresce bright red under ultraviolet (UV) light and blue light (360–460 nm), while green color morphs (usually female) do not. In all color morphs, the suctorial disc glows green-yellow. The red glow of the males matches the red glow of encrusting algae in their nesting areas, while the suctorial disc may be a signaling system. The green and red fluorescence observed in red lumpsuckers is the rarest fluorescent pattern and is only seen in 17 families of marine fishes. Pacific Spiny Lumpsuckers are cryptically colored under broad-spectrum light; our observed fluorescence suggests a potential avenue of communication and camouflage in an environment where red light is absent or rare.

Lepeophtheirus (Copepoda: Caligidae) associated with fish: global infection patterns, parasite-host interactions and geographic range

Lepeophtheirus Nordmann, 1832 is a genus of sea lice that have been reported to cause parasitic disease problems for fish farming and the fishery industry. This first global investigation on Lepeophtheirus species associated with fish and infestation patterns, parasite-host interactions and geographic ranges linked to these ectoparasites covered articles published from 1940 to 2022. The total of 481 samples of Lepeophtheirus spp. comprised 49 species of these ectoparasites and were found parasitizing 100 teleost fish species from 46 families and 15 orders. Globally, a total of 9 Lepeophtheirus species were found in farmed fish (1 species occurred only in farmed fish and 8 species in both farmed and wild fish) and 48 in wild fish. The highest numbers of occurrences of Lepeophtheirus were in Serranidae and Pleuronectidae. L. pectoralis and L. salmonis were the species with widest geographic distribution. Host specificity was an important factor in the geographic distribution of L. salmonis. Most of the parasite species showed specificity for host fish families, as well as specificity for geographic regions. Little is known about many Lepeophtheirus species compared to the economical important L. salmonis. This could be an obstacle to developing improved management control strategies for the parasite in the fish farming industry, in addition to the diminishing knowledge of parasite taxonomy in many regions.

Extensive involvement of CD40 and CD154 costimulators in multiple T cell-mediated responses in a perciform fish Larimichthys crocea

CD40 and CD154 are well-characterized costimulatory molecules involved in adaptive humoral immunity in humans and other mammals. These two costimulatory molecules were found to be originated from teleost fish during vertebrate evolution. However, the functionality of fish CD40 and CD154 remains to be explored. In this study, we identified the CD40 and CD154 homologs (LcCD40 and LcCD154) from large yellow croaker (Larimichthys crocea), a marine species of the perciform fish family. The LcCD40 and LcCD154 share conserved structural features to their mammalian counterparts, and are widely expressed in immune-relevant tissues and leukocytes at different transcriptional levels. Immunofluorescence staining and FCM analysis showed that LcCD40 and LcCD154 proteins are distributed on MHC-II+ APCs and CD4-2+ T cells, and are significantly upregulated in response to antigen stimulation. Co-IP assay exhibited strong association between LcCD40 and LcCD154 proteins. Blockade of LcCD154 with anti-LcCD154 antibody (Ab) or recombinant soluble LcCD40-Ig fusion protein remarkably decreased the MHC-II+ APC-initiated CD4+ T cell response upon Aeromonas hydrophila stimulation, and alloreactive T cell activation as examined by mixed lymphocyte reaction (MLR). These findings highlight the costimulatory role of LcCD40 and LcCD154 in T cell activities in Larimichthys crocea. Thus, the CD40 and CD154 costimulators may extensively participate in the regulation of multiple T cell-mediated immune responses in teleost fish. It is anticipated that this study would provide a cross-species understanding of the evolutionary history of CD40 and CD154 costimulatory signals from fish to mammals.

Parasites with zoonotic potential found in commercially important fish in Tamaulipas, Northeastern Mexico.

Human population is exposed to numerous parasitic ichthyozoonoses. Although Tamaulipas state (northeastern Mexico) is well known for its fishing and aquaculture industry, there are few reports of this type of zoonosis. Therefore, it is imperative to investigate whether the parasites that affect these fish may represent a zoonotic risk for the inhabitants of the area. The objective of this study was to identify molecular and/or morphologically muscle parasites of fish from coastal locations in Tamaulipas, Mexico, and assess the risk of infection for humans. Between 2017 and 2018, 764 individual fish belonging to 28 species were examined for parasites. Collected worms were processed for their identification using morphological characteristics. In addition, partial sequences of the large subunit (28S) ribosomal RNA gene were obtained from some species to corroborate their identity. Prevalence and mean intensity of all registered infections were calculated. A total of seven species of parasites were found: cestodes (Poecilancistrium caryophyllum), trematodes (Clinostomum tataxumui, Clinostomum cichlidorum), nematodes (Eustrongylides sp., Contracaecum sp.) and pentastomids (Sebekia purdieae, Sebekia sp.). Parasites infected 10 species belonging to different fish families (Ariidae, Centrarchidae, Centropomidae, Cichlidae, Eleotridae, Ictaluridae, Mugilidae and Sciaenidae). Congeneric species of parasites or related to those registered in this study have been identified as zoonotic agents in other regions of the world. Despite the low levels of infection (2.6-16.6% prevalence and 1-5.5 parasites per infected host), there is a latent risk of transmission to humans, so it is recommended to avoid eating raw or undercooked fish meat.

Fish classification using extraction of appropriate feature set

<span>The field of wild fish classification faces many challenges such as the amount of training data, pose variation and uncontrolled environmental settings. This research work introduces a hybrid genetic algorithm (GA) that integrates the simulated annealing (SA) algorithm with a back-propagation algorithm (GSB classifier) to make the classification process. The algorithm is based on determining the suitable set of extracted features using color signature and color texture features as well as shape features. Four main classes of fish images have been classified, namely, food, garden, poison, and predatory. The proposed GSB classifier has been tested using 24 fish families with different species in each. Compared to the back-propagation (BP) algorithm, the proposed classifier has achieved a rate of 87.7% while the elder rate is 82.9%.</span>

Off-flavors and lipid components in rainbow trout (Oncorhynchus mykiss) reared in RAS: Differences in families of low and high lipid contents

Recirculating aquaculture systems (RAS)s have become important in land-based fish production. Unfortunately, RAS-farmed fish accumulate off-flavors in their flesh. Off-flavor compounds geosmin (GSM) and 2-methylisoborneol (MIB) are lipophilic compounds and their concentrations need to be controlled in RAS. Therefore, a useful area of study would be the expected impact of total lipid contents and fatty acids in the fish on the accumulation of these off-flavor compounds. The objective of this research was to study the relationships between off-flavor compounds, lipid contents and fatty acids, both at individual and family levels, in rainbow trout (Oncorhynchus mykiss) reared in an experimental RAS.This study showed that 1) the fish and families with high lipid contents accumulated high concentrations of off-flavor compounds, especially when the off-flavor compounds were expressed as contents of total lipids. The overall concentrations of off-flavors ranged from 0.1 to 3.9 ng g−1 ww (GSM) and from 0.1 to 2.4 ng g−1 ww (MIB). 2) The concentrations of polyunsaturated fatty acids (PUFA) and n-3, which are considered health-promoting groups of fatty acids, were lower in fish individuals and families with high lipid content and higher in fish individuals and families with low lipid contents. Therefore, excessive lipid contents may reduce the nutritional value of the fish. 3) Reduced levels of GSM correlated with increased levels of PUFA and n-3 and decreased levels of monounsaturated fatty acids (MUFA, a health-wise neutral effect), and n-6:n-3 ratio. These are highly favorable relationships for aquaculture: high concentrations of health-promoting fatty acids were related to lower off-flavor concentrations. The results imply that changes induced by selective breeding in lipid content may impact both the fatty acid profiles and off-flavor compounds in rainbow reared in a RAS, but large-scale genetic studies are needed to confirm the potential genetic basis of these relationships.

Distribution Patterns of Reef Fish Larvae in the Dipolog Srait, Philippines

The composition, abundance and distribution of reef fish were strongly influenced by the trends in salinity, temperature and mixing regimes of the water during the three oceanographic cruises conducted in the vicinity of the marine reserve networks of Dipolog Strait. Forty-seven families of reef fish larvae were identified. Carangidae, Labridae, Scaridae, Gobiidae and Apogonidae were the top five most abundant larvae comprising 64.7 % of the total number of reef fish larvae collected. Shifts in the dominance of the top five most abundant reef fish families occurred primarily between the northeast and southwest monsoons coinciding with the changes in the temperature profiles of the water column. Abundance of reef fish larvae showed variability across the three sampling periods due to the succession of the dominant species of reef fish larvae. Fluctuations in salinity brought about by the transition from Northeast to Southwest monsoon period could explain the variation. Density distribution of reef fish larvae significantly increased with the increasing depth of the mixed layer during northeast monsoon period. The downwelling off the coast of southern Negros in February and April cruises contributed to the high abundance of reef fish larvae in this part of the strait, while the uniform mixing of the water column in June 2010 at southwest monsoon resulted in the weakening of density gradient of reef fish larvae.The study demonstrated the variable responses of the reef fish larvae to the gradients of chlorophyll in the Dipolog Strait. A better understanding on the retention mechanism of reef fish larvae along the coast of southern Negros, where the main marine reserve networks exist, is provided by the present study.

Multiple paternity in superfetatious live-bearing fishes.

Superfetation, the ability to carry several overlapping broods at different developmental stages, has evolved independently multiple times within the live-bearing fish family Poeciliidae. Even though superfetation is widespread among poeciliids, its evolutionary advantages remain unclear. Theory predicts that superfetation should increase polyandry by increasing the probability that temporally overlapping broods are fertilized by different fathers. Here, we test this key prediction in two poeciliid species that each carry two temporally overlapping broods: Poeciliopsis retropinna and P. turrubarensis. We collected 25 females per species from freshwater streams in South-Eastern Costa Rica and assessed multiple paternity by genotyping all their embryos (420 embryos for P. retropinna; 788 embryos for P. turrubarensis) using existing and newly developed microsatellite markers. We observed a high frequency of unique sires in the simultaneous, temporally overlapping broods in P. retropinna (in 56% of the pregnant females) and P. turrubarensis (79%). We found that the mean number of sires within females was higher than the number of sires within the separate broods (2.92sires within mothers vs. 2.36 within separate broods in P. retropinna; and 3.40 vs 2.56 in P. turrubarensis). We further observed that there were significant differences in the proportion of offspring sired by each male in 42% of pregnant female P. retropinna and 65% of female P. turrubarensis; however, this significance applied to only 9% and 46% of the individual broods in P. retropinna and P. turrubarensis, respectively, suggesting that the unequal reproductive success of sires (i.e. reproductive skew) mostly originated from differences in paternal contribution between, rather than within broods. Together, these findings tentatively suggest that superfetation may promote polyandry and reproductive skew in live-bearing fishes.

Emerging marine protected areas of eastern Indonesia: Coral reef trends and priorities for management

Indonesian coral reefs are under pressure from illegal, unregulated and unreported fishing, the use of destructive fishing practices, land-based pollution, coastal development and climate change. Marine protected areas (MPAs) are necessary to allow habitat recovery and fish stock replenishment. Through the United States Agency for International Development Sustainable Ecosystems Advanced Project (2016–2021), Indonesia worked to improve fisheries productivity and sustainable livelihoods within the three provinces of Maluku, North Maluku and West Papua, where 13 new coral reef MPAs were designed for multiple use, with a zoning system to support biodiversity conservation and sustainable fisheries. At the time of writing in mid-2021, regulations to prohibit fishing within the no-take areas (NTAs) were not yet implemented. This paper presents baseline and trends in percent coral cover and reef fish density and biomass in the MPAs. In 2020, overall coral cover had increased from 42% to 45% across all MPAs. The average target fish biomass across all NTAs had declined from 1709 ( ± 176 SE) kg per hectare in 2017 to 884 ( ± 76 SE) kg per hectare in 2020, representing a significant decline of about 48%. Large and significant declines in many target fish families across multiple MPAs are reflective of unsustainable levels of exploitation. It is evident that management plans need to be implemented with adequate enforcement and stakeholder engagement to stem the decline of target species and to secure livelihoods for local fishing communities.

Tetrodotoxin Poisoning in Mainland France and French Overseas Territories: A Review of Published and Unpublished Cases

Tetrodotoxin is one of the most potent neurotoxins in the aquatic world. This review of published and unpublished reports aims to describe the poisoning cases that have occurred in mainland France and overseas territories. Six articles were included, with 13 poisoning events, individuals or collective (number (n) = 53 patients). Moreover, 13 unpublished poisoning events from toxicovigilance networks were found (n = 17). All cases happened in overseas territories: French Guyana (n = 7), New Caledonia (n = 11), Reunion (n = 35) and French Polynesia (n = 17). The median age was 36 years. The most frequent signs were neurological (81.8%), digestive (54.5%) and general (52.3%). Three cases of dysgueusia and nine cases of urogenital discomfort were observed in French Polynesia. Twelve severe cases were reported, including seven deaths. Only three events (11.5%) were documented by a tetrodotoxin assay. Two families of fish accounted for 91.6% of the poisonings: 33.3% due to the Diodontidae family and 58.3% to the Tetraodontidae family. Although rare, information and collection campaigns on tetrodotoxin poisoning are, therefore, essential.

The monophyly of Crenuchinae and description of two new species ofPoecilocharax(Teleostei: Crenuchidae) based on phenotypic and genotypic evidence

AbstractCrenuchinae is a subfamily of the fish family Crenuchidae distributed in the Amazon Basin with pronounced sexual dimorphism and exuberant colour patterns. Recent fieldwork in the tributaries of the Rio Aripuanã drainage, a large tributary of the Rio Madeira (Amazon Basin), resulted in the discovery of two distinctive, undescribed species of the crenuchin genus Poecilocharax, which are formally described herein, combining morphological and molecular data. These are the first representatives of Crenuchinae discovered after a gap of 57 years and the first records of Poecilocharax from the tributaries of the right bank of the Rio Amazonas draining the Brazilian crystalline shield. Based on a taxonomic review including all species of the subfamily, we provide an expanded morphological diagnosis for Crenuchinae. This now includes characteristics related to the lateral-line canals of head and body, the number of dorsal-fin rays and sexually dimorphic traits. In addition, we review previous characteristics used to diagnose Crenuchus and Poecilocharax, providing comments on their polarity and distribution across the subfamily. A dichotomous key is provided for the first time for species of Crenuchinae.

Diverse parentage relationships in paternal mouthbrooding fishes.

While mouthbrooding is not an uncommon parental care strategy in fishes, paternal mouthbrooding only occurs in eight fish families and is little studied. The high cost of paternal mouthbrooding to the male implies a low risk of investment in another male's offspring but genetic parentage patterns are poorly known for paternal mouthbrooders. Here, we used single-nucleotide polymorphism genetic data to investigate parentage relationships of broods of two mouthbrooders of northern Australian rivers, mouth almighty Glossamia aprion and blue catfish Neoarius graeffei. For N. graeffei, we found that the parentage pattern was largely monogamous with the brooder male as the sire. For G. aprion, the parentage pattern was more heterogeneous including observations of monogamous broods with the brooder male as the sire (73%), polygyny (13%), cuckoldry (6%) and a brood genetically unrelated to the brooder male (6%). Findings demonstrate the potential for complex interrelationships of male care, paternity confidence and mating behaviour in mouthbrooding fishes.