Plecoglossus Research Articles

The use of environmental DNA of fishes as an efficient method of determining habitat connectivity

This study demonstrated the use of environmental DNA (eDNA) to determine habitat connectivity for migration of fishes between the sea and river. Environmental DNA is DNA fragments released by fishes in water, which can be used as a species-specific marker of the presence/absence of the target species. A year-round water sampling regime at 15 sites on the Yodo River, Japan, was conducted to determine whether three major man-made barriers on the river inhibited the migration of fishes using species-specific detection of DNA fragments from three target migrant species, temperate seabass, Lateolabrax japonicus, flathead grey mullet, Mugil cephalus, and ayu, Plecoglossus altivelis altivelis. The presence/absence of eDNA from target species was consistent with known patterns of species’ seasonal migration. The detection of the DNA of temperate seabass and flathead grey mullet at sites upstream of the dam closest to the river mouth indicated successful upstream migration of these species via a fish ladder bypassing the dam. On the other hand, DNA of these two species was not detected from the upstream side of the two remaining dams, which are not equipped with fish ladders. Ayu is the only species among the three target species with a land-locked population in Lake Biwa located at the headwater of Yodo River. Ayu DNA was detected at most of the sites in the freshwater area during the warm months; however, in the coldest month of February, eDNA was only detected in the uppermost site of Yodo River at the southern tip of Lake Biwa. The eDNA we detected at this site suggests that it was derived from juvenile ayu spending their winter months in the lake. These results suggest that the eDNA analysis presented here can accurately track the seasonal migration of fishes in a river, demonstrating its application as an indicator of habitat connectivity for fishes in association with man-made barriers in a river. The sampling of eDNA involves merely scooping a tank full of water; therefore, it is a simple, rapid, and cost-effective method for long-term monitoring of habitat connectivity associated with the construction of barriers in a river.

Identification and expression analysis of IRAK-4 cDNA and its gene from the ayu Plecoglossus altivelis altivelis

Interleukin-1 receptor-associated kinase 4 (IRAK-4) is an important component of the mammalian innate and adaptive defense system against infectious disease. In this study, ayu Plecoglossus altivelis altivelis IRAK-4 cDNA and genomic DNA were cloned and analyzed. The open reading frame of ayu IRAK-4 cDNA encodes 463 amino acids, including a death domain and a serine/threonine protein kinase domain of the mammalian IRAK-4 motif. The ayu IRAK-4 gene comprises 11 exons, and was found to be very similar to vertebrate IRAK-4 genes described thus far. Ayu IRAK-4 mRNA was expressed in all tissues, and predominantly in the gill, heart, intestine, whole kidney, and spleen. At 12 h after immersion challenge with Flavobacterium psychrophilum, ayu IRAK-4 mRNA expression in the whole blood was up-regulated (21.6-fold) compared to the control. The present study suggests that ayu IRAK-4 may be involved in the immune response.

Cathelicidin modulates the function of monocytes/macrophages via the P2X7 receptor in a teleost, Plecoglossus altivelis.

Cathelicidins (CATHs) are a family of endogenous antimicrobial peptides that are capable of both direct bacteria-killing and immunomodulatory effects. P2X7 receptor (P2X7R) is a mediator of CATH in mammalian immune cells. Here, we studied the function and regulation of CATH in head kidney-derived monocytes/macrophages (MO/MФ) from ayu, Plecoglossus altivelis. We investigated the chemotaxis of MO/MФ in response to ayu CATH (PaCATH), and found that PaCATH had a dose-dependent effect on MO/MФ chemotaxis with the optimal concentration of 10.0 μg/ml. The qPCR and Western blot analysis revealed that PaCATH inhibited the expression of ayu P2X7R (PaP2X7R) at both mRNA and protein levels. Knockdown of the PaP2X7R expression in ayu MO/MФ by RNA interference not only significantly inhibited the chemotactic effect of PaCATH on MO/MФ, but also obviously reduced the effect of PaCATH on the phagocytosis, bacteria-killing, respiratory burst, and cytokine expression of ayu MO/MФ. Our study revealed that the immunomodulatory effect of fish CATH is mediated by P2X7R.

Radiological impact of the nuclear power plant accident on freshwater fish in Fukushima: An overview of monitoring results

Radionuclide (131I, 134Cs, and 137Cs) concentrations of monitored freshwater fish species collected from different habitats (rivers, lakes, and culture ponds) in Fukushima Prefecture during March 2011–December 2014 (total 16 species, n = 2692) were analyzed to present a detailed description of radionuclide contamination after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, and to elucidate species-specific spatiotemporal declining trends of 137Cs concentration for their respective habitats. Low concentrations of 131I (≤24 Bq kg−1-wet) were detected from only 11 samples collected during March–June 2011, demonstrating that 131I transferred to freshwater fish were not intense. In river and lake fishes, a more gradual decrease and higher radiocesium (134Cs, 137Cs) concentrations were observed than in culture pond fishes, which strongly implied that radiocesium in freshwater fish species was mainly bioaccumulated through the food web in the wild. During 2011–2014, percentages above the Japanese regulatory limit of 100 Bq kg−1-wet for radiocesium in river and lake fish (14.0% and 39.6%, respectively) were higher than in monitored marine fish (9.9%), indicating longer-term contamination of freshwater fish species, especially in lakes. Higher radiocesium concentrations (maximum 18.7 kBq kg−1-wet in Oncorhynchus masou) were found in the northwestern areas from the FDNPP with higher deposition. However, radiocesium contamination levels were regarded as 1–2 orders of magnitude less than those after the Chernobyl accident. Lagged increase of 137Cs concentration and longer ecological half-lives (Teco: 1.2–2.6 y in the central part of Fukushima Prefecture) were observed in carnivorous salmonids (O. masou, Salvelinus leucomaenis), whereas a rapid increase and decrease of 137Cs concentration and shorter Teco (0.99 and 0.69 y) were found in herbivorous and planktivorous osmerids (Plecoglossus altivelis, Hypomesus nipponensis) with younger age at maturity. Comparison of Teco among salmonids, osmerids, and cyprinids suggests that, in addition to the fish feeding habits and life-cycles, hydraulic conditions in rivers and lakes (e.g., turnover time), which are expected to affect radiocesium concentration in prey items, are an important factor affecting the 137Cs decreasing rate of freshwater fish.

Metagonimus yokogawai (Trematoda: Heterophyidae): From Discovery to Designation of a Neotype.

Metagonimus yokogawai (Katsurada, 1912) Katsurada, 1912 (Trematoda: Heterophyidae) is parasitic in the small intestine of mammals including man and birds in Far Eastern Russia, Korea, Japan, China, and Taiwan. In the present study, the metacercariae and adults of M. yokogawai were redescribed to designate a neotype of this fluke together with reviews of previous studies including study histories from the first discovery to now. We particularly, attempted to review the study histories and morphological descriptions of M. yokogawai for the species validity, and compared with the morphological characteristics and life cycles of the closely related species, Metagonimus takahashii and Metagonimus miyatai. Finally, we proposed a differential key for the 8 known Metagonimus species distributed in East Asia. Metacercariae were obtained from the body muscles of sweetfish (Plecoglossus altivelis) collected in the Asahi River at Takebe-cho, Kita-ku, Okayama City, Okayama Prefecture, Japan. Adults were recovered from the small intestine of Syrian golden hamsters, to which the metacercariae had been fed 14 days before. A neotype was selected out of the present adult specimens. The Asahi River at Takebo-cho became the type locality of M. yokogawai. In conclusion, the present review shows that M. yokogawai, M. takahashii, and M. miyatai are valid and discriminated by means of morphological characteristics.

Temporal variations of fish assemblage in the surf zone of the Nakdong River Estuary, southeastern Korea

To assess temporal variations in fish assemblages, fish samples were collected on a monthly basis in the surf zone of the Nakdong River Estuary in 2004. Surveys were conducted at two sites during day and night neap tides using a 10-m beach seine. In total, 2397 specimens (8146.0 g) comprising 27 species and 16 families were collected during the study period. The dominant fish species were Mugil cephalus, Plecoglossus altivelis, Favonigobius gymnauchen, Opsariichthys uncirostris amurensis, and Hyporhamphus sajori, which accounted for 84.6% of the total number of individuals. The fish sampled were primarily small species or the early juveniles of larger species. The species composition and abundance varied greatly, with a peak in the number of individuals in July (summer) and January (winter), and the peak in biomass during July (summer). The catch rate was low in the spring and autumn months due to the low abundance of the dominant species recorded. A cluster analysis revealed that the fish assemblages were characterized by distinct seasonal groups reflecting the reproductive habits of adult fishes. Fish abundance did not significantly differ between the two sites, although a significant difference in their abundance was detected between day and night, with more fish specimens collected at night than during the day at both sites. The Nakdong River Estuary is an important ecosystem for small and/or juvenile fishes, providing a habitat within the estuary suitable for their development and migration.

Expressed sequence tag analyses of three leukocyte subpopulations in ayu Plecoglossus altivelis altivelis, separated by monoclonal antibodies

Ayu Plecoglossus altivelis altivelis are one of the most economically important fish for freshwater aquaculture in Japan. We conducted expressed sequence tag analyses of three leukocyte subpopulations, thrombocytes, neutrophils, and B lymphocytes in ayu using a next generation sequencer. The sequencing and de novo assembly yielded 22,494, 22,733, and 16,505 contigs from the thrombocyte, neutrophil, and B lymphocyte cDNA libraries, respectively. Pathways involving endocytosis, phagosomes, and lysosomes, were found in all three cDNA libraries using pathway analysis. The thrombocyte cDNA library contained 2894 unique sequences, including CXC chemokine receptor 4 and MHC class II. Cytokine and cytokine receptor genes such as interleukin (IL)-1β, IL-8, IL-1 receptor (IL-1R), IL-8RA, and IL-8RB were found among the 3056 unique sequences of the neutrophil cDNA library. Typical B lymphocyte related genes such as B cell linker protein, immunoglobulin (Ig) M, IgD and transforming growth factor β were found in the 1590 unique sequences of the B lymphocyte cDNA library. In summary, a large number of immune-related genes were identified from the three leukocyte cDNA libraries. Our results represent a valuable sequence resource for understanding the immune system function in ayu.

Inherent noise appears as a Lévy walk in fish schools.

Recent experimental and observational data have revealed that the internal structures of collective animal groups are not fixed in time. Rather, individuals can produce noise continuously within their group. These individuals’ movements on the inside of the group, which appear to collapse the global order and information transfer, can enable interactions with various neighbors. In this study, we show that noise generated inherently in a school of ayus (Plecoglossus altivelis) is characterized by various power-law behaviors. First, we show that individual fish move faster than Brownian walkers with respect to the center of the mass of the school as a super-diffusive behavior, as seen in starling flocks. Second, we assess neighbor shuffling by measuring the duration of pair-wise contact and find that this distribution obeys the power law. Finally, we show that an individual’s movement in the center of a mass reference frame displays a Lévy walk pattern. Our findings suggest that inherent noise (i.e., movements and changes in the relations between neighbors in a directed group) is dynamically self-organized in both time and space. In particular, Lévy walk in schools can be regarded as a well-balanced movement to facilitate dynamic collective motion and information transfer throughout the group.

Molecular characterization of a transmembrane C-type lectin receptor gene from ayu (Plecoglossus altivelis) and its effect on the recognition of different bacteria by monocytes/macrophages

C-type lectin receptors (CTLRs) play vital roles in immune responses as pattern-recognition receptors (PRRs). In this study, we identified a novel C-type lectin receptor (PaCTLRC) gene from ayu, Plecoglossus altivelis. Predicted PaCTLRC is a single transmembrane receptor with a typical carbohydrate recognition domain (CRD) at its C-terminus. Sequence comparison and phylogenetic tree analysis showed that PaCTLRC was most closely related to Atlantic salmon (Salmo salar) CLRC, but was significantly different from two other ayu CTLRs, aCLR and PaCD209L. PaCTLRC transcript was detected in all tested tissues and cells, with high levels in the liver; and its expression was significantly altered upon Vibrio anguillarum infection. Refolded recombinant PaCTLRC (rPaCTLRC) agglutinated three types of Gram-positive bacteria (Listeria monocytogenes, Staphylococcus aureus and Streptococcus iniae) and four types of Gram-negative bacteria (Aeromonas hydrophila, Escherichia coli, V. anguillarum and Vibrio parahaemolyticus) in a Ca2+-dependent manner in vitro, and Gram-positive bacteria were shown to be biologically relevant ligands for PaCTLRC. rPaCTLRC bound to d-mannose, d-galactose, l-fucose, N-acetyl-d-glucosamine (GlcNAc), lipopolysaccharide (LPS) and peptidoglycan (PGN), exhibiting a relative binding strength to d-mannose and PGN. d-Mannose, l-fucose, GlcNAc, LPS and PGN could inhibit the agglutinating activity of rPaCTLRC, while d-galactose did not functioned. PaCTLRC neutralization using anti-PaCTLRC IgG resulted in the inhibition of phagocytosis by ayu monocytes/macrophages (MO/MΦ) of S. aureus but not of E. coli, and produced a consistently higher survival rate of S. aureus than that of E. coli. d-Mannose, LPS and PGN treatment had no significant influence on the phagocytosis of ayu MO/MΦ. These results suggest that PaCTLRC may serve as a Gram-positive bacteria-preferred PRR which is involved in pathogen recognition and signal transduction in ayu MO/MΦ.

Molecular characterization and functional analysis of a novel C-type lectin receptor-like gene from a teleost fish, Plecoglossus altivelis

C-type lectin-like receptors (CLRs) are important pathogen pattern recognition molecules that recognize carbohydrate structures. However, the functions of these receptors in fish keep less known. In this study, we characterized a novel CLR from a teleost fish, Plecoglossus altivelis (ayu), tentatively named PaCD209L. The cDNA of PaCD209L is 1464 nucleotides (nts) in length, encoding a polypeptide of 281 amino acid residues with a calculated molecular weight of 31.5 kDa. Multiple alignment of the deduced amino acid sequences of PaCD209L and other related fish CLRs revealed that the PaCD209L sequence had typical characteristics of fish CLRs, but without Ca2+-binding sites. Sequence comparison and phylogenetic tree analysis showed that PaCD209L shared the highest amino acid identity (44%) with rainbow trout (Oncorhynchus mykiss) CD209 aE PaCD209L transcripts were detected in all of the tissues examined, mainly expressed in the brain and heart. Upon Vibrio anguillarum infection, PaCD209L transcripts were upregulated in all tested tissues and in monocytes/macrophages (MO/MΦ). We prepared recombinant PaCD209L (rPaCD209L) by prokaryotic expression and raised antiserum against PaCD209L. Western blot analysis revealed that native PaCD209L was glycosylated, and its protein expression significantly increased in ayu MO/MΦ upon V. anguillarum infection. In addition, rPaCD209L was able to bind Gram-positive and Gram-negative bacteria in the absence of Ca2+. After PaCD209L was blocked by anti-PaCD209L IgG, the phagocytosis and bacterial killing activity of MO/MΦ significantly decreased. These results suggest that PaCD209L plays an important role in the regulation of MO/MΦ functions in ayu.

Discrimination of the Stock Origins and Growth of Ayu Plecoglossus altivelis altivelis in the Nagara River

Discrimination of the Stock Origins and Growth of Ayu Plecoglossus altivelis altivelis in the Nagara River

Regional Variation of Length Composition and Growth History of Larval and Juvenile Ayu Plecoglossus altivelis altivelis in Lake Biwa

Regional Variation of Length Composition and Growth History of Larval and Juvenile Ayu Plecoglossus altivelis altivelis in Lake Biwa

서부 DMZ 인접지역의 담수어류 출현양상

Appearance patterns of freshwater fish were investigated in the western Demilitarized Zone (DMZ) adjacent areas near Imjin River in Gyeonggi-do, Korea, of 2014. A total of 61 species belonging to 14 families were found in the river during the survey. The dominant and subdominant species were Zacco platypus (Relative abundance, 20.3%) and Zacco koreanus (12.6%), respectively. Other abundant species include Rhinogobius brunneus (9.2%), Pungtungia herzi (4.4%), Acheilognathus yamatsutae (4.4%), and Pseudogobio esocinus (4.0%). Among the residing species, 24 species (39.3%) were endemic to Korea; and 1 species, Carassius cuvieri, was non-indigenous species. Hemibarbus mylodon is a natural monument, and Lethenteron reissneri, Acheilognathus signifer, Pseudopungtungia tenuicorpa, Gobiobotia brevibarba, G. macrocephala, and G. naktongensis are endangered species in Korea. In addition, Anguilla japonica and Plecoglossus altivelis are catadromous and amphidromous species, respectively. Among the investigated sites, the lower part of Sami Stream (St. 5, 6) and Gunnarm-dam region (St. 11, 14) are particularly valuable for the conservation of species diversity, because many fish species (33~42 species) including a natural monument and several endangered species inhabit in these regions.

Food Availability for Larvae of Plecoglossus altivelis ryukyuensis in the Yakugachi River of Amami-oshima Island, Japan

Food Availability for Larvae of Plecoglossus altivelis ryukyuensis in the Yakugachi River of Amami-oshima Island, Japan

Habitat Choice by Ayu Plecoglossus altivelis between Even and Uneven Streambeds

Habitat Choice by Ayu Plecoglossus altivelis between Even and Uneven Streambeds

Molecular characterization of the liver-expressed antimicrobial peptide 2 (LEAP-2) in a teleost fish, Plecoglossus altivelis: Antimicrobial activity and molecular mechanism

Liver-expressed antimicrobial peptide 2 (LEAP-2) is widespread in fish and plays an important role in the host's innate immune system. In this study, full-length cDNA for LEAP-2 (PaLEAP-2) gene was cloned and sequenced from ayu, Plecoglossus altivelis. PaLEAP-2 mRNA was detected in a wide range of tissues, with the highest level of transcripts found in the liver. Upon induction by Vibrio anguillarum, its expression significantly increased in the liver, kidney, spleen, gill, and heart, but decreased in the intestine. The PaLEAP-2 mature peptide was chemically synthesized; it exhibited selective antimicrobial activity against various bacteria in vitro. PaLEAP-2 at high concentration reduced the bacterial load and improved the survival rate of V. anguillarum-infected ayu. Moreover, it inhibited the expression of mRNAs for TNF-α and IL-1β in V. anguillarum-infected ayu, both at high and low concentrations. PaLEAP-2 induced hydrolysis of the pET-22b plasmid DNA and bacterium genomic DNA. These results suggest that PaLEAP-2 plays a role in ayu immune responses against bacterial infection.

Panfish: Spot On

There's something about him when he's fried. You leave that skin on, cut him, and just eat him from the inside out. Spot is good, buddy, can tell you that. --overheard at the Bayford Oyster House, Virginia, November 21, 2011 I fry mine hard and eat the bones, the tail, and all ... always cook that head because like crunching on it. love crunching on it! leave the tail head and tail, leave on. --Katie White, Painter vie., Virginia, August 6, 2014 [ILLUSTRATION OMITTED] Late summer the phone rings in the Bayford Oyster House on the Eastern Shore of Virginia. Bayford, H. M. Arnold answers. Yes ma'am, he says a few seconds into the conversation, I don't have any spot today. They don't seem to be running. Nobody know has them. have some hardheads though, if you want to drive down and get them. Thank you. H. M. shakes his head and sits down in his plastic chair by the stainless steel counter where he shucks oysters for the winter trade from Thanksgiving to New Years. afternoon steams August hot, a bit of breeze ruffles the water on Nassawadox Creek outside the door. tide is rising and soon enough will seep under the sills and into the dock end of the venerable shucking house, sheeting over the old concrete floors, compelling H. M. and his visitors first to walk on boards and then to slosh their way past the soft-shell crab shedding tanks now all but closed down for the season. Tank, the monumental Chesapeake Bay retriever who lives up the hill, stands in the boat launch with a chunk of pine branch clenched in his jaws, waiting for someone--anyone will do--to seize the wood and pitch it into the water. Strangers shy away from the massive dog; regulars ignore him. Tank perseveres. And so do the callers seeking spot, a panfish deeply savored in this corner of the world. phone rings. Bayford, H. M. answers. Spot, it seems, have diminished in their numbers since 1890, when a fish census noted: Large numbers of young spot from 3 to 4 inches in length were seined in the bay at Cape Charles City. They were present in abundance, numerous schools being seen ... As a pan fish, the spot is the most highly prized of all fishes sold in the Norfolk market.' Writing from North Carolina, Hugh M. Smith reported in 1907, The spot, which gets its name from the round mark on its shoulder, inhabits the east coast of the United States from Massachusetts to Texas, and is one of the most abundant and best known of our food Smith concludes, The spot ranks high as a food and is by many persons regarded as the best of the pan fishes. There is a good demand for North Carolina spots in Baltimore, Washington, and other markets of the Chesapeake region, and the fish is also rated high as a salt fish for local consumption. (2) Spot, another observer reported, the smallest members of the croaker family that are sold with any regularity. Most specimens weigh only about 1/4 pound. Spots are easy to recognize by their spot right behind the gill opening. (3) spot's distinguishing markings, Pooh Johnson, oysterman and cook in Onancock, Virginia, asserts are the marks of Christ's fingertips imprinted when He divided the loaves and fishes for the multitude in Mark 6:41. (4) Communion of a different variety causes H. M.'s phone to ring. Uncommonly common in the lower Chesapeake and in North Carolina's sounds, the spot (also known regionally as Jimmy, chub, roach, Goddy, and Lafayette) lives inshore from late spring through autumn and winters in deeper offshore waters during the cold months: The waters of the Chesapeake Bay off Norfolk, Virginia, are such prime spot fishing grounds that out-of-town menus often list this small, sweet fish as 'Norfolk Spot' ... Prior to spawning season in the fall, the spot takes on a golden color much like its cousin the croaker. At that time the fish are often referred to as 'Ocean View Yellow Bellies' because they congregate to feed off Ocean View, a Norfolk neighborhood on the Chesapeake Bay. …

Modeling the preference of ayu (Plecoglossus altivelis) for underwater sounds to determine the migration path in a river

Water sounds are believed to be important in triggering the upriver ascent behavior of migratory fish species. Modeling the effect of underwater sound on fish preference represents a promising technique to determine migratory paths for the comprehensive analysis of river habitat suitability. In this study, we aimed to determine the preference and weight of underwater sounds by laboratory experiments using adult and juvenile ayu (Plecoglossus altivelis). A watercourse with an underwater speaker installed at one end was used for the experiments. Sound was emitted from the speaker at different sound pressure levels. The sound sources included pure tones (100Hz, 200Hz, 400Hz, and 800Hz), white noise, recorded sound from a weir on the Fushino River, and recorded sound at a fish ladder on the Misumi River (Japan). The results showed that juvenile and adult ayu avoided the pure sound of 100Hz and recorded sound of the Fushino River weir. In contrast, both adults and juveniles preferred the pure sound of 200Hz and recorded sound of the fish ladder. Moreover, by comparing the obtained quantitative preference parameters for sounds, we found that adult ayu expressed higher preference for sound than juveniles. We designed a procedure to calculate sound preference and built it into our fish behavior simulation model on geographic information system (GIS) software. We believe that the model could successfully reproduce observed fish migration behavior in rivers. This technique could be used for designing an underwater soundscape to attract fish to the entrances of fish ladders or to keep fish away from hydropower plants.

河川での低濃度濁水の発生に対するアユの反応事例：野外における河川区間スケールでの実験

河川での低濃度濁水の発生に対するアユの反応事例：野外における河川区間スケールでの実験

Comparison of food habits between native Amur three-lips (Opsariichthys uncirostris uncirostris) and non-native largemouth bass (Micropterus salmoides) in Lake Biwa, Japan

The Amur three-lips (Opsariichthys uncirostris uncirostris ) is an endemic subspecies in Japan and native to the river systems of the Lake Biwa–Yodo River. The population of three-lips in Lake Biwa has decreased, primarily due to habitat degradation and introduction by competitive, non-native predators, such as largemouth bass (Micropterus salmoides ). However, the effects of bass introduction on the three-lips are unclear. We investigated the food habits of the three-lips and compared them with those of sympatric non-native largemouth bass in Lake Biwa. A total of 145 three-lips and 178 largemouth bass were sampled during the summer and fall of 2013. Fish prey, particularly ayu (Plecoglossus altivelis altivelis ), was predominant in the three-lips diet, followed by terrestrial insects. Decapods (i.e. , prawn and shrimp), ayu and demersal fish (e.g. , gobids) composed a substantial proportion of bass diets. No significant dietary overlaps were found between the two predators. Our results suggest that differences in food habits between the two species may result from differences in feeding behavior; the three-lips is a mobile predator that forages mainly on nektonic and suspended food, whereas largemouth bass is an ambush predator that forages on both nektonic and benthic prey. We referred the results of three-lips diets in Lake Biwa in a previous study and suggest that changes in fish fauna, due to introduction by non-native largemouth bass, may have affected prey availability for the three-lips.