Lutjanus Johnii Research Articles

¬Occurrence of Microplastic Ingestion by Commercial Fish Species from the Pangempang Estuary in Indonesia

The aim of this study was to assess the occurrence of microplastic in digestive organs (esophagus to intestine) of popular marine commercial fish species: Jack (Caranx SP.), blackspot snapper (Lutjanus fulviflamma), coral grouper (Epinephelus carallicala), golden snapper (Lutjanus johnii) and pickhandle barracuda (Sphyraena jello) from Pangempang Estuary in Indonesia. To separate the microplastic particles, each sample was digested using alkaline digestion solution, filtered on Whatman paper and then dried. Microplastic particles in the processed digestive organ contents were identified and enumerated using a dissecting stereo microscope. Microplastics were observed in 94 % of fish digestive organs sampled: 100 % jacks (n = 10), 80 % blackspot snapper (n = 10), 100 % coral grouper (n = 10), 90 % golden snapper (n = 10) and 100 % pickhandle barracuda (n = 10). In these fish samples we found in average of 41 ± 6.0, 26 ± 11.0, 15 ± 2.0, 11 ± 1.0 and 14 ± 2.0 SE microplastic particles per individual and an average of 499.5 ± 94.4, 501.5 ± 198.8, 83.6 ± 18.4, 79.8 ± 11.6 and 40.2 ± 25.0 SE microplastic particles per kg fish weight, in jacks, blackspot snapper, coral grouper, golden snapper and pickhandle barracuda, respectively. Fiber was the most dominant type accounting for 78.6 % of all observed microplastics. Microplastic beads were not detected. The correlation of the average consumed microplastic and the average fish weight per species showed a negative relationship (R2 = 0.36), but was not significant (p-value = 0.28). Our finding suggests that demersal fish like jacks, blackspot snapper and coral grouper may have ingested a higher quantity of microplastic particles compared to pelagic species like pickhandle barracuda. HIGHLIGHTS This study demonstrates the presence of microplastic particles in 5 commercially important fish in a tropical estuary of Kalimantan Island in Indonesia Fiber was the most dominant type of microplastic Demersal fish may have ingested a higher quantity of microplastic particles compared to pelagic species GRAPHICAL ABSTRACT

Application of SPMs and BRPs to Access Overexploitation Risk Faced by Lutjanus johnii (Bloch, 1792) in Pakistan: A Sustainable Fishery Management Perspective

Application of SPMs and BRPs to Access Overexploitation Risk Faced by Lutjanus johnii (Bloch, 1792) in Pakistan: A Sustainable Fishery Management Perspective

A comparative analysis of osteocranium morphology in Lutjanus johnii (Bloch, 1792) and Lutjanus gibbus (Forsskal, 1775) inhabiting different habitats

The snapper species Lutjanus gibbus (L. gibbus) is commonly found in coastal areas characterized by coral reefs and clear water, while Lutjanus johnii (L. johnii) resides in mangrove waters with murky conditions and strong currents. The habitat plays a crucial role in influencing body shape and ossification patterns in fish. Therefore, this study aimed to examine the differences in the cranial bone morphology between the two Lutjanus fish species that resided in contrasting habitats. The fish samples were collected from local fishermen operating in the waters of Pulo Aceh, Aceh Besar, Indonesia. Following capture, the fish were transported and landed at Lampulo Fishing Port in Banda Aceh for further analysis. For each species, a total of 5 fish samples were randomly selected, and thorough cleaning of scales and muscles was performed before the drying of the bones. These dried cranial bones were then photographed, edited, and subjected to detailed analysis. The study showed that, of the 23 observed skull bone characters, 15 characters showed the differences in the cranial bones of the two snapper species, including the pre-ethmoidal, ethmoidal lateralis, prefrontal, supraorbital, nasal, ethmoidal, sphenoticum, crista occipital, lacrimal, inter-opercular, opercular, preopercular premaxilla, endopterygoideum, and hyomandibular. Significant differences were observed in the bones composing the eyes, nose, jaws, and ventral region of the head. In the mangrove snapper (L. johnii), the bones associated with the eyes (orbitospenoidal, supraorbital, and prefrontal) were less developed, while those related to the nose (nasal, ethmoidal, ethmoidal lateralis, pre-ethmoidal) showed well-developed characteristics. The coral snapper L. gibbus displayed a relatively small but thicker premaxilla bone in the jaw region, along with smaller bones in the ventral head area.Keywords:OsteologyMorphologyEcomorphologyOsteocraniumMaxillare

Caligid sea lice (Copepoda: Caligidae) from golden snapper Lutjanus johnii (Bloch) in Australian waters, with the recognition of Sinocaligus Shen, 1957 as a junior synonym of Caligus Müller, 1785.

Two species of sea lice are reported from the golden snapper Lutjanus johnii (Bloch) in Australian waters. One was represented by chalimus larvae, adult males and extremely slender females in which the genital complex is scarcely wider than the fourth pedigerous somite. These females are adult as they carry paired spermatophores and are identified as Caligus dussumieri Rangnekar, 1957 on the details of their appendages. Caligus dussumieri was formerly placed in the genus Sinocaligus Shen, 1957 but the characters supporting the validity of this genus are not robust, so it is here proposed to treat it as a junior subjective synonym of Caligus and transfer its species as: Caligus formicoides Redkar, Rangnekar & Murti, 1949, Caligus dussumieri Shen, 1957, Caligus caudatus (Gnanamuthu, 1950) new combination and Caligus timorensis (Izawa, 1995) new combination. All these species can be placed in the C. bonito-species group within Caligus. Caligus rivulatus Pilla, Vankara & Chikkam, 2012 is recognized as a junior subjective synonym of C. dussumieri. A new species, C. auriolus n. sp. is also described and this is placed in the C. diaphanus species-group. A key to species of this species-group is provided which indicates that C. auriolus n. sp. is most closely related to C. stromatei Krøyer, 1863 but the latter can be distinguished by the slender abdomen of the female and by the more complex myxal process on the maxilliped in the male.

Population dynamics and stock assessment of Red snapper (Lutjanus johnii) in the Bay of Bengal Bangladesh waters

Red snapper (Lutjanus johnii) is one of the most significant commercial fish species in the marine waters of Bangladesh. A comprehensive understanding of the biology and dynamics of fish is important for the effective management of the fishery. Therefore, it would be the first study on this highly valuable commercial species to draw stock status and assessment of reference points in the upper Bay of Bengal, Bangladesh using three different length-based methodological approaches which are TropFishR (Tropical Fisheries Analysis with R), LBSPR (Length-based Spawning Potential Ratio), LBI (Length based Indicators), and a catch-based method DB-SRA (Depletion-based Stock Reduction Analysis). An allometric growth pattern (b=2.66) was observed in the length-weight relationship of Red snapper. The VBGF (von Bertanlanffy Growth Function) life history parameters for Red snapper were L∞=99.33 cm, k=0.16 year−1, and based on LCCC (Length Converted Catch Curve) analysis, the total mortality (Z=0.59 year−1), natural mortality (M=0.24 year−1) and fishing mortality (F=0.35 year−1) were estimated. The results show that this fishery is currently likely to be overfished due to overexploitation and the stock’s spawning biomass (SPR=28%) is below the target reference point because most of the catch (72%) was found to have under the maturity level. This study recommended a length to catch between 51 and 62 cm and proposed a yearly landing limit of 175 mt as OFL (Over Fishing Limit) for the next ten years in line with the annual fishing ban to raise the stock’s biomass over the Bmsy level for maintaining sustainable yield of 271 mt as MSY.

An outbreak of lymphocystis disease virus infection in cultured juvenile John's snapper (Lutjanus johnii) in Malaysia

This study reports an outbreak of lymphocystis disease virus infection in cultured juvenile John's snapper (Lutjanus johnii) in Malaysia. In mid-January 2021, approximately 19,000 juvenile John's snapper exhibited signs of lethargy and isolating themselves from the schooling group, developed lymphocysts all over the body and fins, and died. The outbreak started at day 3 after the introduction of fish into the hatchery, and the severity of the disease was observed between day 7 and 14, resulting in 53% mortality. No bacteria was isolated, while a low prevalence of protozoan parasite was observed at 5% of fish samples. Histopathology examination revealed focal nodular dermal fibroblast hypertrophy with karyomegaly and hyaline capsule formation. Basophilic intracytoplasmic inclusions were observed in the diseased fish. PCR and sequence analyses revealed that all affected fish were positive to lymphocystis disease virus (LCDV), which was absent from the clinically healthy fish. Phylogenetic analysis revealed that the isolates from this outbreak were from the cluster of LCDV genotype 2. This paper reports the first documentation of LCDV infection in cultured John's snapper in Malaysia. Farmers and authorities should beware of the impacts LCDV infection, as it can cause high mortality and economic losses in cultured fish.

Status of fish diversity and fishing gears in the fishery of Nanthikadal Lagoon, Mullaitivu, Sri Lanka

<p class="Default">The Northern coast of Sri Lanka is home to a larger number of lagoons, totalling up to 804 km². Nanthikadal lagoon is a significant lagoon that exists in the coastal zone of the Mullaitivu District between 9° 17’ N and 80° 48’E. Species occurrences and their types are good indicators to express the health status of the lagoon ecosystem. The present investigation was carried out for the first time to record the finfish and shellfish diversity, diversity indices and the fishing gears used to capture these fishes in the Nanthikadal lagoon by collecting monthly samples from the fish landing centres from September 2017 to August 2019. Collected species were identified using FAO species identification field guide. During the field survey, the number of organisms caught from all species were also counted. Diversity indices such as Dominance, Simpson, Shannon and Evenness were calculated by using PAST software. Fish numbers were graphically compared through cluster analysis by Unweighted Pair Group Method with Arithmetic mean (UPGMA). Fishing gears used and details on mesh size of nets were collected by using questionnaire and face to face interview with the fishermen. Seventeen finfish and five shellfish species belonging to seventeen families were identified during the study period. <em>Tilapia mossambica </em>made the highest percentage contribution (29.34%). The minimum contribution was reported by species such as <em>Portunus pelagicus</em>, <em>Scylla serrata</em>, <em>Scatophagus argus</em>, <em>Lutjanus johnii</em>, <em>Tricanthus biaculeatus </em>and <em>Chanos chanos </em>(&lt;1%). The highest and lowest abundance was found in post-monsoon and pre-monsoon periods respectively. Simpson index and Shannon index were high in the monsoon season. <em>Strongylura strongylura </em>and <em>Gerres abbreviates </em>showed a close relationship based on month-wise cluster analysis. Cast net was the most commonly used, and legal fishing gear. Part-time fishermen actively participated in shrimp capturing from brackish water. In the present study, the important components of the lagoon fishery such as fish and usage of fishing gears were analyzed to determine the present status of Nanthikadal lagoon fishery. These findings will be helpful for stakeholders in this region for sustainable fishery management and ultimately supporting the Ministry of Fisheries and Aquatic Resource Development by providing required fundamental information to develop a lagoon management plan in the future.

Extraction and Characterization of Natural Calcium Phosphate Materials from &lt;i&gt;Lutjanus johnii&lt;/i&gt; and &lt;i&gt;Lutjanus sebae&lt;/i&gt; Fish Bone Bio-Wastes

Fish processing by-products, such as fish bone waste is usually considered as waste and will be disposed without fully utilizing it. Indeed, this by-product can serve as a cheap bio-resource for the production of high-value product, for instance, as an inexpensive source of calcium phosphate material. In this research, Lutjanus johnii and Lutjanus sebae bones were subjected to thermal calcination to yield different calcium phosphate products. XRD, FTIR and HRTEM-SAED results revealed that biphasic HAp/β-TCP mixture was obtained by heat treatment of Lutjanus johnii bone while a single-phase HAp was prepared from Lutjanus sebae bone. In addition, it was shown that both Lutjanus johnii and Lutjanus sebae bones had a merit in producing B-type carbonated composition that is advantageous for biomedical application. EDX result further corroborated the existence of inorganic elements such as Mg, Na and Sr. With their unique composition, the calcined products deriving from Lutjanus johnii and Lutjanus sebae bones can be further employed to form bioceramic scaffolds for bone engineering applications.

Percentage of the bycatch and discard composition in artisanal bottom trap fisheries

Data on bycatch in the fishing effort required to manage fisheries resources. Unfortunately, the data on small-scale and traditional fisheries is still lacking. It makes it challenging to make fishing policies and regulations. Survey activities and experimental fishing were conducted to determine and analyze the composition of the main catch, bycatch and discarded by the local fisher's bottom traps in Sibolga, North Sumatra, Indonesia. Five units of the trap with a size of 150 cm x 100 cm x 50 cm (length x width x height) were used to collect fish data. These five trap units operated in the fishing ground, where local fishers usually operate their fishing gear. The fishing operation carried out within 1 mile of the coastline with water depths ranging from 7-10 meters. The duration of trap setting around 5-7 days for each fishing operation. A motorboat operated with a weight of 5.8 GT. The results showed that the total bottom trap catch consisted of 329 individuals with a total weight of 151.4 kg and 12 demersal fish species. The main catch was 148 individuals (88.9 kg), or 44.7% of the total catch during the experiment i.e. Chepalapholis urodeta, Ephinephelus areolatus, Epinephelus chlorostigma, Plectropomus leopardus, Ephinepelus coioides, Lates calcarifer, Lutjanus malabaricus, and Lutjanus erytropterus. The bycatch was 151 individuals (57.1 kg) or 46.1% i.e. Lethrinus obsoletus, Lutjanus ehrenbergii, Acanthurus auranticavus, Platax teira, Nemipterus japonicus, Scarus rivulatus, Lutjanus johnii, Siganus canaliculatus, Caesio cuning, and Taeniura lymma.While the discarded catch amounted to 30 individuals (5.4 kg) or 9.2% i.e. Naso brevirostris, Diodon holocanthus, and Diadema setosum. The bycatch utilization obtained by fishers was 83.4%, and the unutilized was 16.6%. The percentage of fish sizes worthy for consumption was 135 individuals (74.6%), and the size unworthy for consumption was 46 individuals (25.4%).Keywords:Fishing groundFishing gear Fishing operation Main catchTrap

Infection of the parasitic isopods on commercial fishes of the northern part of the east coast of India.

The online version contains supplementary material available at 10.1007/s12639-021-01463-1.

Integrated analyses of SNP-genotype and environmental data in a continuously distributed snapper species (Lutjanus johnii, Bloch, 1792) reveals a mosaic of populations and a challenge for sustainable management

AbstractUnderstanding population structure is important for predicting the outcomes of anthropogenic development, harvest, and environmental change on the abundance of fisheries species. Logically, the use of several data sources is best for delineating population structure, but combining across data types adds extra challenges as results can be incongruent. Here, genetic and environmental markers were used to test hypotheses about population structure in a collection of 523 tropical inshore finfish (Lutjanus johnii) across northern Australia from 20 locations. Redundancy analyses (RDA) were used to statistically test for correlations among data sources providing a basis for reconciliation and insights into ecological and evolutionary processes. Genomic data (10349 SNP loci) revealed low, but significant genetic divergence (max FST 0.0402) between 16 locations. A total of 12 putative contiguous biological stocks were proposed whose distributions were correlated with IMCRA bioregions but not to existing regions used for management of the fishery. RDA showed a significant correlation between environmental markers (otolith chemistry and parasite abundances) and SNP genotype in two of three region-wide analyses supporting the proposed stock structure, and suggesting that L. johnii may be locally adapted to the heterogeneous environment. These findings are significant for the conservation of the commercially and recreationally important L. johnii and can be used to guide future fisheries management actions.

Identification of Fish and Shellfish Larvae from Mangroves Using DNA Barcodes

Ram, R.; Pavan-Kumar, A.; Jaiswar, A.K.; Gireesh-Babu, P.; Krishna, G., and Chaudhari, A., 2020. Identification of fish and shellfish larvae from mangroves using DNA barcodes. Journal of Coastal Research, 36(5), 1106–1110. Coconut Creek (Florida), ISSN 0749-0208.Mangrove ecosystems support coastal and marine fisheries by providing feeding, breeding, and recruitment grounds for a great diversity of fish species. Globally, mangroves are declining from anthropogenic factors, causing a reduction in fish production. Baseline data of fish species that use mangroves as nursery or breeding grounds is a prerequisite for monitoring the health of mangrove ecosystems. However, identification of fish and shellfish larvae up to species level is difficult because of a lack of distinguishing morphological characters. In the present study, fish and shellfish larval diversity from selected mangrove zones of the northwest coast of India was characterized by the DNA barcoding approach. Around 53% (n = 33) of sampled individuals could be identified up to species level without ambiguity. The study concluded that many commercially and ecologically important fish and shellfish species, such as, Pampus argenteus, Pampus chinensis, Sillago sihama, Lutjanus johnii, Boleophthalmus boddarti, and Penaeus monodon, are utilizing mangroves of the northwest coast of India as nursery grounds. The results of the present study provide baseline data for fish diversity of mangroves of the northwest coast of India.

Capillaria appendigera n. sp. (Nematoda: Capillariidae) from the goldbanded jobfish Pristipomoides multidens (Day) (Lutjanidae) and new records of other intestinal capillariids from marine perciform fishes off Australia.

Based on light and scanning electron microscopical studies, a new nematode parasite, Capillaria appendigera n. sp. (Capillariidae), is described from the intestine of the goldbanded jobfish Pristipomoides multidens (Day) (Perciformes, Lutjanidae) from the Arafura Sea West, off the northern coast of Australia. The new species, belonging to the subgenus Procapillaria Moravec, 1987, differs from other congeneric species from fishes mainly in the length (0.92-1.13mm), shape and structure of the spicule, obtuse spines on the spicule sheath and the structure of eggs. It is characterised, in the male, by the presence of two well-developed dorsolateral caudal lobes, a pair of lateral papillae, a heavily sclerotised spicule with many rough transverse grooves covering almost the entice spicule surface (except for spicule ends), a spinose spicule sheath, and in the female, by a subterminal anus, mostly the presence of a large vulval appendage and by eggs (size 54-69×27-33µm) encapsulated by a conspicuous light-coloured superficial layer. Capillaria appendigera n. sp. is the 12th nominal species of capillariids recorded from fishes in Australian waters and the second known capillariid species parasitising fishes of the perciform family Lutjanidae. In addition, four unidentifiable, morphologically different types of capillariid females, probably representing undescribed species, were recorded from the intestines of marine fishes off the northern coast of Australia: Capillariidae gen. sp. 1 and Capillariidae gen. sp. 2 from Lutjanus johnii (Bloch) and L. malabaricus (Bloch & Schneider), respectively (both Lutjanidae), Capillariidae gen. sp. 3 from Protonibea diacanthus (Lacépède) (Sciaenidae) and Capillariidae gen. sp. 4 from Rachycentron canadum (Linnaeus) (Rachycentridae).

New tissue-dwelling species of Philometra Costa, 1845 and Philometroides Yamaguti, 1935 (Nematoda: Philometridae) from marine perciform fishes off the northern coast of Australia.

Based on light and scanning electron microscopical studies, three new species of philometrids (Nematoda: Philometridae) are described from females collected in marine perciform fishes off the northern coast of Australia: Philometra gracilis n. sp. and Philometroides branchiarum n. sp. from tissues behind the gills and gill arches, respectively, of the John's snapper Lutjanus johnii (Bloch) (Lutjanidae), and Philometroides stomachicus n. sp. from the stomach wall of the blackspotted croaker Protonibea diacanthus (Lacépède) (Sciaenidae). Philometra gracilis differs from other congeners described from the Lutjanidae mainly in the presence of large caudal projections, short gravid females (28-42mm long), the oesophageal gland extending anteriorly far anterior to the level of the nerve-ring, the site in the host and its geographical distribution. Philometroides branchiarum is mainly characterised by the possession of conspicuous, sclerotised oesophageal teeth and very short gravid females (6-8 mm long), whereas P. stomachicus can be differentiated by the body length of gravid females (85-90 mm), the length of the oesophagus (2.67mm) representing 3% of the body length, the maximum width/body length ratio of gravid females (1:28-32), cuticular bosses densely distributed throughout the body but absent from the oesophageal region, the absence of oesophageal teeth and caudal projections, and the site in the host. The presence of P. gracilis and P. branchiarum in L. johnii and that of P. stomachicus in P. diacanthus confirm the possibility of the coexistence of more philometrid species in different sites within sympatric specimens of one and the same definitive host.

Successful spawning of John’s snapper Lutjanus johnii (Bloch, 1792) under controlled conditions

Broodstock of the John’s snapper Lutjanus johnii were raised in sea cages from wild collected juveniles of the species. Individual fishes were tagged using passive integrated transponders (PIT), cannulated and gonadal biopsies were examined periodically for assessing the maturity status. The matured fishes were shifted from cages and maintained in indoor FRP tanks. Females were given two doses of human chorionic gonadotropin (hCG) and ovaprim @ 800 - 900 IU kg-1 and 1.25ml kg-1 respectively. Males were given only hCG in a range between 400 and 600 IU kg-1. Two successful spawning were obtained with 80-85% fertilisation rate. In both the trials, embryonic development was observed to be arrested before hatching which could be attributed to nutritional deficiency of the broodfishes and high water temperature in the spawning tank.

Two gonad-infecting species ofPhilometra(Nematoda: Philometridae) from marine fishes off the northern coast of Australia

Two different gonad-infecting species of Philometra Costa, 1845 were collected from the ovary of marine perciform fishes, the blackspotted croaker Protonibea diacanthus (Sciaenidae) and the John’s snapper Lutjanus johnii (Lutjanidae), from off the northern coast of Australia. Nematodes (males and females) from P. diacanthus represent a new taxon, Philometra protonibeae n. sp., which is mainly characterized by the body length of the males (3.37–3. 90 mm), broad, equally long spicules (length 126–141 μm) and the shape and structure of the gubernaculum with a dorsally lamellate distal tip. The nematodes (only females) from L. johnii may represent an undescribed species, but, because of the absence of conspecific males, they could not be specifically identified. Philometra protonibeae is the fifth nominal gonad-infecting species of this genus recorded from marine fishes in Australian waters and the seventh species of these parasites described from fishes of the family Sciaenidae.

The complete mitochondrial genome of the golden snapper Lutjanus johnii (Perciformes: Lutjanidae)

We describe the complete mitochondrial genome of the golden snapper Lutjanus johnii. It was assembled from approximately 1.4 million reads produced by Ion Torrent next generation sequencing. The complete genome was 16,596 bp in length consisting of 13 protein-coding regions, 22 tRNA, 12S and 16S rRNA as well as two non-coding regions. The A+T base content (52.8%) is similar to other teleosts.

Use of otolith shape for stock identification of John's snapper, Lutjanus johnii (Pisces: Lutjanidae), from the Persian Gulf and the Oman Sea

The otoliths of John's snapper (Lutjanus johnii) from the Persian Gulf and the Oman Sea were studied to evaluate whether otolith shape can be used to differentiate populations. John's snapper is a relevant commercially exploited species in the Arabian Sea, and the identification of different stocks is a major issue for fishery management. Otolith weight was used to examine the growth rate of both populations and as an indicator of similar ambient water composition. Otolith contours were obtained using wavelet functions, from the finest (WLT 1) to coarsest (WLT 9) scales, and then compared by principal components (PCA) using a canonical discriminant analysis (CDA) for each scale. No significant differences were noted in the otolith weight between the two populations (ANCOVA, P>0.05). The variability of the finest scales (WLT 1–3) was very high and showed a low percentage of classification (61%). The intermediate scales (WLT 4–6), and WLT 8 provided the best results; whilst the highest classification percentage was found in WLT 4 and WLT 8 (76% and 77%, respectively). The results of this study enable us to conclude that both populations should be considered separate stocks.

Is there a cryptic species of the golden snapper (Lutjanus johnii)?

For centuries, morphology-based fish identification has been applied without molecular evaluation. Many studies showed that specimens with a similar morphology are frequently found to be quite genetically distinct. One of the fish species that still remains taxonomically problematic is a commercial snapper species, Lutjanus johnii. Because of morphological ambiguities among local fish taxonomists in Malaysia, we examined the ability of the cytochrome oxidase I (COI) gene to genetically examine the taxonomic status of L. johnii. A 626-base pair COI region was successfully amplified and aligned with conspecific sequences that were retrieved from GenBank. The phylogenetic tree obtained showed two major clusters; the first cluster consists of L. johnii from Straits of Malacca, Thailand, Australia, and China while the second cluster comprises L. johnii from China and India. The latter group showed sequence divergence greater than 3.5%. After observing this, we suspected that there might be a cryptic species between the South China Sea and Indian Ocean. This is the first molecular report concerning the commercial species of snapper, L. johnii, in Malaysia, which had only gained provisional recognition from morphological examination.

Dactylogyrids (Monogenoidea: Polyonchoinea) parasitising the gills of snappers (Perciformes: Lutjanidae): Species of Euryhaliotrema Kritsky &amp; Boeger, 2002 from the golden snapper Lutjanus johnii (Bloch) off northern Australia, with a redescription of Euryhaliotrema johni (Tripathi, 1959) and descriptions of two new species

Three species of Euryhaliotrema Kritsky & Boeger, 2002 (Monogenoidea: Dactylogyridae) were collected from the gills of four golden snapper Lutjanus johnii (Bloch) (Lutjanidae) from the marine and brackish waters off Darwin, Northern Territory, Australia. Type-specimens of Ancyrocephalus johni Tripathi, 1959 apparently have not survived and the possibility existed that the species was based on specimens representing more than one species. Euryhaliotrema johni (Tripathi, 1959) (sensu Young, 1968) was redescribed and determined to most likely represent A. johni, originally described from the River Hooghly, Diamond Harbour, India. Two new species were described. Euryhaliotrema longibaculoides n. sp. was most similar to Euryhaliotrema longibaculum (Zhukov, 1976) Kritsky & Boeger, 2002 from Lutjanus spp. from the western Atlantic Ocean. It differed from E. longibaculum by having a male copulatory organ (MCO) with an elongate comparatively delicate shaft and a bulbous base (MCO U- or J-shaped with funnel-shaped base in E. longibaculum). Based on the comparative morphology of the haptoral sclerites, Euryhaliotrema lisae n. sp. was most similar to Euryhaliotrema cryptophallus Kritsky & Yang, 2012 from the gills of the mangrove red snapper Lutjanus argentimaculatus (Forsskål) from the South China Sea. Euryhaliotrema lisae differed from E. cryptophallus by having a copulatory complex with an obvious weakly sclerotised J-shaped MCO (MCO cryptic, delicate, and with a shaft comprising about one counterclockwise ring in E. cryptophallus).