Ablennes Research Articles

An integrative taxonomic study on needlefishes (Belonidae) unveils two new species within the genus Ablennes from the Indian Ocean

The needlefish genus Ablennes remains monotypic, characterized by the globally distributed flat needlefish known as Ablennes hians. Their taxonomy has been mired with ambiguities due to the greater-than-average morphological variations observed in samples from different regions. Utilizing integrated taxonomic methods relying on mitochondrial molecular markers, it was revealed that the species initially perceived as a single entity is, in fact, a complex comprising at least three different species. In this context, we introduce two new species: Ablennes joseberchmansis sp. nov. and Ablennes gracalii sp. nov., They are morphologically distinct: in view of the morphometry and meristic characteristics. A. joseberchmansis sp. nov. and A. gracalii sp. nov. display distinct differentiation characteristics from A. hians in terms of dorsal fin, nostril position, dorsal fin origin, vertebrae count, scale counts, head length, eye diameter, interorbital width, maxilla length, dorsal ray height, depth at pelvic origin, lower lobe of the caudal fin, and caudal peduncle depthcaudal peduncle depth. These variations highlight their unique morphological traits and aid in their differentiation within the genus Ablennes. We assessed genetic relationships using a Maximum likelihood (ML) phylogenetic tree, revealing three distinct clades of morphological differences in Ablennes specimens from different morphological groups. The genetic variation, as represented by Kimura 2 parameter (K2P) distances, within the three Ablennes species spans from 6.5% to 9.4%. More specifically, we observed a 7.5% genetic difference between A. hians and A. joseberchmansis sp. nov., and a 6.5% distinction between A. hians and A. gracalii sp. nov. The interspecies divergence between the two newly identified species measured at 9.4%. These findings, which showcase the genetic distinctions among the three morphologically distinct Ablennes specimens, provide strong confirmation for the existence of three separate species within the Ablennes genus of needlefish in the Indian Ocean.

Fishery, population dynamics and stock assessment of flat needlefish Ablennes hians (Valenciennes, 1846) from the south-eastern Arabian Sea off Kerala coast, India

The age, growth, mortality parameters and stock status of Ablennes hians(Valenciennes, 1846) were assessed by using length frequency, catch, and effort datacollected from the commercial catches along the coast of Kerala (south-eastern ArabianSea) during 2015-2017. The growth parameters, L∞, K and t0 were estimated at 133.9 cm TL,0.72 yr-1 and -0.0026 yr, respectively. The instantaneous natural mortality (M), total mortality(Z), fishing mortality (F) and current exploitation rate (Ecur) were estimated as 0.95 yr-1,2.78 yr-1, 1.83 yr-1 and 0.66, respectively. Length at capture (Lc50) was estimated at 77.58cm TL, which is greater than Lm50. Beverton and Holt yield per recruit analysis, indicated thatmaximum Y/R could be obtained at an exploitation rate (Emax) of 0.75, suggesting scope foran increase in exploitation. In this analysis, spawning stock biomass (SSB) was not takeninto consideration, which is essential for maintaining recruitment in the future. In the presentstudy, E0.1 (0.61) and Ecur (0.66) were nearly equal, indicating that the fishery is running atan economic reference point i.e., maximum economic yield (MEY). Thompson and Bellprediction model showed that at the current level of exploitation, the SSB was reduced by20.49% and hence, there is no scope for further increase in fishing efforts to maintain the SSBat a relatively safe and sustainable level. The analysis revealed the maximum sustainableyield (MSY) of this species as 90.26 t, which can be obtained by increasing the present levelof fishing effort by 1.3 times but would result in the depletion of the SSB to a critically lowlevel of 15.65%. Therefore, a precautionary safe level of exploitation (E0.1), estimated at 0.61for the species, is recommended. Keywords:Belonidae, Fishery management, Population dynamics,Spawning stock biomass, Stock status

Engine size and proportion of catch kept affects fish catch in Pujada Bay, Davao Oriental

This study aimed to calculate the catch per unit effort (CPUE) and determine the status of the finfish population in Pujada Bay. This was conducted through semi-structured interviews, focus group discussion, and validation of actual catch sampling/logbook information taken from the interviews. Fishers mostly catch bigeye scad (Selar crumenopthalmus), flat needlefish (Ablennes hians), horseface unicornfish (Naso fageni), purple eyebrowed tuskfish (Choerodon zamboangae), silver pomfret (Pampus argenteus), and African red snapper (Lutjanus agennes) in Barangay Tamisan and skipjack tuna (Katsuwonus pelamis) and yellowfin tuna (Thunnus albacares) in Barangay Macambol. Results relating socioeconomic and fisheries variables to catch did not produce significant results. Further analysis using regression showed that normal catch was influenced by engine size and the proportion of catch kept by fishers (P≤0.05). Analysis of CPUE of fishers in Tamisan also revealed significant differences with the best catch having the highest CPUE (1.57 kg/hr), normal catch (0.62 kg/hr), and worst catch (0.27 kg/hr) with haul time of 5.46 hours. This was also similar in the case of Macambol which showed significant differences in the catches e.g. best catch having the highest CPUE (7.08 kg/hr), normal (4.37 kg/hr), and worst catch (2.54 kg/hr) with haul time 9.23 hours. Most species caught in Pujada Bay between Tamisan and Macambol are piscivores, other species are molluscivores, omnivores, carnivores, planktivores, and herbivores. Engine size in horsepower and proportion of catch kept by fishers affected the number of fish caught.

Influence of Hook Number on Species Composition, Catch Rate, and Size of Needlefishes in the Gulf of Mannar, India

Naganandhini, V.; Muthupandi, K.; Vasanth, K.; Neethiselvan, N.; Padmavathy, P., and Radhakrishnan, K., 2023. Influence of hook number on species composition, catch rate, and size of needlefishes in the Gulf of Mannar, India. Journal of Coastal Research, 39(3), 502–508. Charlotte (North Carolina), ISSN 0749-0208. The contribution of needlefishes from the Gulf of Mannar coast has been remarkable and is presently exploited by pelagic longlines. The J hook is extensively used in longline fishing in the Indian region to capture carnivore fishes, including needlefish. Catch rate significantly differed between the hook numbers. In this context, three hook numbers of 10 J, 11 J, and 12 J were studied from January to May 2022. Results showed that the Ablennes hians was the dominant fish caught (47.9%), followed by Tylosurus crocodiles (22.2%), T. choram (16.6%), and Strongylura strongylura (13.3%); weight-based catches of T. crocodiles (39.7%) were dominantly higher, followed by A. hians (35.9%), T. choram (13.8%), and S. strongylura (10.6%). The two-way ANOVA results revealed that a significant (p <0.05) difference occurred between the hook number and the number of species caught. The largest number of fish were caught with hook number 12 (3769), followed by hook number 11 (2745) and hook number 10 (1445). However, the highest weight of 2749.74 kg was recorded with hook number 11 and the lowest of 1602.65 kg in hook number 10 (p <0.05). This is related to fewer fish caught with hook number 10 and heavy fishing pressure on subadults (<50 cm) due to the use of hook number 12. Considering the maximum total length and weight, the optimum hook number for the commercial exploitation of needlefishes was hook number 11. The catch per unit effort disproportionately increased with the increasing of the hook number; the significant higher contribution of 48.25 individuals/1000 hooks was from hook number 12, whereas hook numbers 11 and 10 were 35.13 individuals/1000 hooks and 18.51 individuals/1000 hooks, respectively.

Diet composition and feeding habits of flat needlefish Ablennes hians (Valenciennes, 1846) (Beloniformes: Belonidae) in the Southeastern Arabian Sea

Diet composition and feeding habits of flat needlefish Ablennes hians (Valenciennes, 1846) (Beloniformes: Belonidae) in the Southeastern Arabian Sea

Expansion of the flat needlefish Ablennes hians (Valenciennes, 1846) distribution in the eastern Mediterranean

The flat needlefish Ablennes hians was recorded for the first time from the coast of Turkey in the eastern Mediterranean. Two specimens were captured, one in May 2021 and the second in April 2022. One of the specimens was preserved and deposited in fish collection, while only the photograph of the other was obtained.

Catch sustainability of the main fish species exploited by handline in locations with distinct management systems in Brazil

Ecological Risk Assessment for the Effects of Fishing (ERAEF) is an assignment process of magnitudes and probabilities to the damaging effects of fishing activities, and is used to identify and prioritize the risks of fishing to marine ecosystems. Productivity and susceptibility analysis (PSA), part of ERAEF, assumes that the susceptibility of a species to impact, and its productivity, determines the potential for recovery of the species if its population collapses. In this study, PSA of the species most caught by the handline fishery of the artisanal fleet from the state of Ceará, Northeast Brazil. Sampling was conducted by monitoring fishing landings from 2017 to 2019 at Mucuripe, Batoque marine protected area (MPA), and Prainha do Canto Verde MPA. The seven productivity attributes were maximum length (Lmax), von Bertalanffy growth coefficient (K), length at first maturity (L50), L50/Lmax, intrinsic growth rate (r), fecundity, and trophic level. The six susceptibility attributes were: availability (the geographic overlap of fishing activity according to species distribution), percentage of individuals caught larger than the L50, management strategy, commercial category, frequency of occurrence, and abundance. The productivity values ranged from 1.24 to 2.88. The species Scomberomorus cavalla showed the lowest productivity, while Holocentrus adscensionis showed the highest productivity with a high r and K. Susceptibility values ranged from 1.18 to 2.27. The species Lutjanus synagris caught at Batoque MPA showed the highest susceptibility, which was a high commercial category score, frequency of occurrence, and abundance at this site. Vulnerability values ranged from 1.71 to 3.46. The species S. cavalla, L. analis, and Ablennes hians were the most vulnerable, ranked as high risk at all sites. H. adscensionis was the least vulnerable at all sites. The vulnerabilities were not statistically different across the sites, suggesting a lack of effective management measures in the MPA.

Length–weight analysis of ten species (Actinopterygii) supporting subsistence fishery in Lakshadweep waters, southern Arabian Sea

The length–weight relations of ten fish species representing eight genera and four families and that formed the backbone of the subsistence fishery in the Lakshadweep islands were estimated. These fishes which included four species of tuna [Katsuwonus pelamis (Linnaeus, 1758); Thunnus albacares (Bonnaterre, 1788); Auxis thazard (Lacepède, 1800); Euthynnus affinis (Cantor, 1849)], three species of needlefishes[Ablennes hians (Valenciennes, 1846); Tylosurus crocodilus (Péron et Leseur, 1821); Tylosurus acus melanotus (Bleeker, 1850)], two species of bait fishes [Spratelloides delicatulus (Bennett, 1832); Spratelloides gracilis (Temminck et Schlegel, 1846)], and one species of halfbeak (Hemiramphus archipelagicus Collette et Parin, 1978) contributed to 96% of the total fish landings. The samples were collected from fish landing centers of ten inhabited islands of Lakshadweep from 2015 to 2017. Katsuwonus pelamis showed isometric growth, S. delicatulus and S. gracilis exhibited positive allometry, while negative allometric growth was seen in other species. The coefficient a of the LWR ranged from 0.001 (A. hians) to 0.035 (T. albacares), while b ranged from 2.7 (T. acus melanotus) to 3.4 (S. delicatulus). The results of the presently reported study provide useful biological information on the stock of ten commercially important pelagic fish species supporting the traditional fisheries in Lakshadweep waters.

Length–weight analysis of ten species (Actinopterygii) supporting subsistence fishery in Lakshadweep waters, southern Arabian Sea

The length–weight relations of ten fish species representing eight genera and four families and that formed the backbone of the subsistence fishery in the Lakshadweep islands were estimated. These fishes which included four species of tuna [Katsuwonus pelamis (Linnaeus, 1758); Thunnus albacares (Bonnaterre, 1788); Auxis thazard (Lacepède, 1800); Euthynnus affinis (Cantor, 1849)], three species of needlefishes[Ablennes hians (Valenciennes, 1846); Tylosurus crocodilus (Péron et Leseur, 1821); Tylosurus acus melanotus (Bleeker, 1850)], two species of bait fishes [Spratelloides delicatulus (Bennett, 1832); Spratelloides gracilis (Temminck et Schlegel, 1846)], and one species of halfbeak (Hemiramphus archipelagicus Collette et Parin, 1978) contributed to 96% of the total fish landings. The samples were collected from fish landing centers of ten inhabited islands of Lakshadweep from 2015 to 2017. Katsuwonus pelamis showed isometric growth, S. delicatulus and S. gracilis exhibited positive allometry, while negative allometric growth was seen in other species. The coefficient a of the LWR ranged from 0.001 (A. hians) to 0.035 (T. albacares), while b ranged from 2.7 (T. acus melanotus) to 3.4 (S. delicatulus). The results of the presently reported study provide useful biological information on the stock of ten commercially important pelagic fish species supporting the traditional fisheries in Lakshadweep waters.

Conversion of mini trawls (Thallumadi) into light fishing craft targeting belonids and hemiramphids along palk bay, southeast coast of India

The needlefish both full beak and halfbeaks support a good fishery in Tamil Nadu and exploited by drift gillnet (Mural valai). In this study, we were focused to document the conversion of Mini trawls (Thallumadi) into light fishing craft targeting Belonids and Hemiramphids along Palk Bay. The detailed survey was conducted in the six landing centres along Palk Bay. The fishing was mainly targeted to catch Tylosurus crocodilus from 2000 to 0300 hrs at the distance of 3-4 NM in the depth of 5 m. After reaching the fishing ground, the fishes are usually aggregated using LED lights. The fishermen use the scoop net to collect the fishes. Catch per unit effort (CPUE) ranged from 36 to 40 kg/Unit and the fishery was dominated by T. crocodilus (85%) followed by Hemiramphus far (9%) and Ablennes hians (6%). The net operating income for this fishery is higher than the mini trawl fishery.

Bangladesh Gets New Marine Fish (Actinopterygii: Teleostei): First Observation of Seven Species from Rocky Tidal Habitats of the St. Martin’s Island, Bay of Bengal

On the northeastern flank of the Bay of Bengal, the St. Martin’s Island, a sedimentary continental formation, is the only maritime island and an Ecologically Critical Area of Bangladesh. Rock beds fringing the island from supratidal to subtidal zone with a subtidal depth around 10 m and presence of non-reef forming scleractinian corals from lower rocky intertidal to about 200–600 m offshore comprise a rich but least-explored rocky tidal habitat. Addressing the knowledge gap, during December 2017, an expedition was conducted to observe fish diversity caught in beach seines, gillnets and drifting handlines. Studying morphological and meristic characters of the collected specimens revealed 7 bony fish species for the first time in Bangladesh and northern seaboard of the Bay of Bengal. These are Ablennes hians, Callionymus erythraeus, Ellochelon vaigiensis, Grammatobothus polyophthalmus, Istiblennius dussumieri, Omobranchus punctatus, and Trichonotus setiger. The family Trichonotidae and the genera Ablennes, Callionymus, Grammatobothus, and Istiblennius, too, represent the first record for Bangladesh. Omobranchus punctatus, I. dussumieri, C. erythraeus and T. setiger were strongly associated with the tidal boulder beds. Grammatobothus polyophthalmus, a flounder threatened by shrimp harvesting, was caught in trawling gillnet operated in the surrounding subtidal waters. Ellochelon vaigiensis, a catadromous mullet known to spend natal stages near shoreline, was collected from a rock-pool. Fish diversity of the St. Martin’s Island is not well understood; the last comprehensive checklist dated back to 1997. Thus, these results remarkably obtained from a cursory expedition entail a thorough diversity assessment of the island.

Benefit-risk associated with the consumption of fish bycatch from tropical tuna fisheries

Mercury, omega-3 (docosahexaenoic acid, DHA and eicosapentaenoic acid, EPA) and macronutrients (fat and proteins) were quantified on a wet weight (ww) basis in 20 species of fish taken as bycatch in tropical tuna fisheries. Based on a hazard quotient taking into account mercury and omega-3 contents, a benefit-risk assessment for the consumption of these pelagic species was conducted for three people categories: young children, children and adults. All fish bycatch were found to be an excellent source of proteins (min‒max = 14.4–25.2 g/100 g fillet), had low omega-6/omega-3 ratios (<1, except for silky shark), and had mercury content below the safety limits defined by sanitary agencies. Silky shark and Istiophoridae had the highest mercury contents (min‒max = 0.029–0.317 ppm ww). Omega-3 contents were the lowest in silky shark (0.2 ± 0.2 mg/100 g fillet) and the highest in striped marlin (3.6 ± 3.2 g/100 g fillet). Billfishes (Istiophoridae, including striped marlin), minor tunas (Scombridae), and Carangidae had the highest omega-3 contents (min‒max = 0.68–7.28 g/100 g fillet). The highest hazard quotient values obtained for silky shark and great barracuda reflected a lower nutritional benefit (i.e., low omega-3 source) than risk (i.e., mercury exposure), making them not advisable for consumption. Eight species had low hazard quotients, and among them cottonmouth jack and flat needlefish were found of high health interest (high protein, moderate fat contents, and low omega-6/omega-3 ratio). A daily serving portion of 85–200 g (according to people category) can be recommended for these species. Batfish, and to a lower extent pompano dolphinfish and brassy chub, can also be consumed safely and would provide greater health benefits than risks. These results advocate for a better access of these species to local populations.

Indication of cryptic taxa within the flat needlefish, Ablennes hians based on analysis of the cytochrome oxidase I region on a wide range of samples

ABSTRACT We analysed the genetic structure with respect to geographic distribution of the flat needlefish, Ablennes hians, previously considered as having a circumtropical distribution. Cytochrome oxidase I (COI) barcode region sequences were constructed for a specimen from the Mediterranean, and a specimen from Japan. The sequences of the studied specimens were compared with 18 barcodes of this species from Barcode of Life Data-systems (BOLD). The results revealed that genetic distances between groups of specimens from different geographic regions can be as high as 10.9%, and in most comparisons were above the widely accepted threshold level of within-species variation. This suggests the occurrence of several cryptic taxa within the Ablennes hians complex.

Morphological and Molecular Description of Rhadinorhynchus hiansi Soota and Bhattacharya, 1981 (Acanthocephala: Rhadinorhynchidae) from Marine Fish off the Pacific Coast of Vietnam

Rhadinorhynchus hiansi Soota and Bhattacharya, 1981 , has remained unknown since its original incomplete description from 2 male specimens collected from the flat needlefish Ablennes hians Valenciennes (Belonidae) off Trivandrum, Kerala, India. Recent collections of fishes along the Pacific coast of Vietnam in 2016 and 2017 produced many specimens of the same species from the striped bonito Sarda orientalis Temminck and Schlegel (Scombridae) off the southern Pacific coast of Vietnam at Nha Trang. We describe females for the first time, assign a female allotype status, and provide an expanded description of males from a larger collection completing missing information on hooks and hook roots, receptacle, lemnisci, cement glands, Saefftigen's pouch, and trunk spines. Specimens of R. hiansi characteristically have no dorsal spines in the posterior field of trunk spines and a long proboscis with 36-48 dorso-ventrally differentiated proboscis hooks per row becoming progressively smaller posteriorly then increasing in size near the posterior end to a maximum at the posterior-most ring. Trunk, testes, and lemnisci in our specimens were considerably larger than those reported in the original description, but the proboscis was relatively smaller. The females had long reproductive system and corrugated elliptic eggs without polar prolongation of fertilization membrane. Energy Dispersive X-ray Analysis (EDXA) demonstrates high levels of calcium and phosphorus in large gallium cut hooks and high levels of sulfur in tip cuts of large and small hooks and in spines. This EDXA pattern is a characteristic fingerprint of R. hiansi. The molecular profile of R. hiansi is described from 18S rDNA and COI genes, and phylogenetic relationships with most closely related species are discussed.

First record of the flat needlefish Ablennes hians (Valenciennes, 1846) from Syrian marine waters (eastern Mediterranean)

BackgroundClimatic changes and human activities have worked to pave the way for alien species to invade new areas far from their native habitats. Belonidae species (Needlefishes), spread into wide water bodies, and some exist in the Mediterranean Sea.MethodOn 18/2/2019, a field trip was performed in the marine waters facing Banyas city, Syria (N: 35°14′35.11“, E: 35°55’12.56”); to collect fish samples using a gillnet, with assistance of fishing boat (9.5 m and 19HP). Fish individuals were identified, the morphometric measurements and meristic counts were recorded.ResultsTwo individuals of the Flat Needlefish Ablennes hians were caught from the marine water facing Banyas city-Syria.ConclusionThis study reveals that the Flat Needlefish A.hians exists in the marine waters of Syria (Eastern Mediterranean). It is recorded for the second time in the Mediterranean Sea, and Suez Canal is thought to be the main root of introduction.

Length-weight analysis of three needlefish species from the Lakshadweep archipelago

Length-weight relationships (LWRs) of three needlefishes belonging to the family Belonidae viz., Ablennes hians, Tylosurus crocodilus and Tylosurus acus melanotus were estimated based on samples exploited from a gill-net fishery in Androth, an island in the Lakshadweep archipelago. The estimated allometric co-efficient b value ranged from 3.047 (T. acus melanotus) to 3.274 (A. hians), and r2 value ranged from 0.911 (T. acus melanotus) to 0.973 (A. hians). The first estimate of LWR for these three commercially exploited needlefish species from the Lakshadweep islands indicate local populations to be fairly robust and forms a basis for future management of fishing stock in the region.

New Distributional Record of Flat Needlefish Ablennes hians (Valenciennes, 1846) (Beloniformes: Belonidae) in the North-Eastern Indian Ocean with Taxonomic Details

Present study is based on five specimens of flat needlefish Ablenneshians collected from Puri North (Lat. 19047′43.062″N, Long. 85049′38.5788″E), Odisha, India on 7 January 2018. Based on morphometric and meristic characters, the specimens were identified as Ablenneshians (family Belonidae), having laterally compressed body with a series of vertical bars, 26 to 27 anal fin rays, 24–25 dorsal fin rays, 13–14 pectoral fin rays, and single lobe of gonad. A.hians can be distinguished from other three species of needlefishes reported from northeast coast of India based on body shape (body strongly compressed laterally in A. hians vs. rounded in cross section in other three species), number of anal fin rays (24–28 in A. hians vs. 15–25), vertical bars on body (a series of vertical bars in A. hians vs. no vertical bars in others except for S. leiura where few vertical bars are present on anterior half of the body). The occurrence of flat needlefish along Odisha Coast revealed the extension of its known geographical distributional range i.e. from noth of Andhra Pradesh in the North-eastern Indian Ocean. Further, it is an addition to the ichthyofaunal biodiversity of northeast coast of India.

Length-weight relationships of five needlefish species from Kerala waters, south-west coast of India

Length-weight relationships (LWRs) were estimated for five needlefish species such as Ablennes hians (Valenciennes, 1846), Tylosurus crocodilus (Péron & Lesueur, 1821), Tylosurus acus melanotus (Bleeker, 1850), Strongylura leiura (Bleeker, 1850), and Strongylura strongylura (van Hasselt, 1823). Specimens were collected on weekly basis from Cochin Fisheries Harbour (Lat. 09056′327″N, Long. 76015′764″E), Munambam Fisheries Harbour (Lat. 10010′965″N, Long. 76010′258″E), Kalamukku (Lat. 09059′924″N, Long. 76014′564″E) and Chellanam (Lat. 09047′950″N, Long. 76016′551″E), between October 2015 to August 2017. Fish were captured by traditional long liner (hook no. IX-XIV) and ring seiner (mesh size 8–24 mm). The estimated allometric co-efficient b values ranged from 3.063 (Tylosurus acus melanotus) to 3.962 (Strongylura leiura) and r2 values ranged from 0.850 (Tylosurus acus melanotus) to 0.992 (Tylosurus crocodilus). All the LWRs were highly significant, with p < .001. In addition, the study provides the first estimate of LWR for Tylosurus acus melanotus and new estimate for other four species of needlefish.

Axinoides euzeti n. sp. (Monogenea: Axinidae) from the gills of the needlefish Tylosurus acus imperialis (Rafinesque) (Belonidae) off Tunisia, with an updated list of hosts and localities for Axinoides spp.

A new axinid monogenean species, Axinoides euzeti n. sp. from the gills of the Mediterranean needlefish Tylosurus acus imperialis (Rafinesque) off the Tunisian coast is described. The new species is most similar in general morphology to A. meservei Price, 1946 from Tylosurus crocodilus fodiator Jordan & Gilbert off the Atlantic Ocean and to A. kola Unnithan, 1957 from Ablennes hians (Valenciennes) off the Indian Ocean. It can be differentiated from A. meservei by the shape of anterior male genital complex armed with several rows of curved spines on the cirrus rather than 3 to 4 rows of slender spines, in having a fewer testes (87-94 vs more than 100 in the drawing of A. meservei) and a body size twice longer than wide. It differs also from A. kola which have a single row of small spines in the cirrus, in having fewer and wider clamps and fewer and smaller testes. A. euzeti represents the first record of a representative of this genus in the Mediterranean Sea. In addition, taxonomic keys and an updated list of hosts and geographic localities for Axinoides species is presented.

Inheritance and phylogenetic analysis of Tylosurus acus melanotus based on the complete mitochondrial genomes

In our research, 17 sets of primers were used to amplify contiguous, overlapping segments of the complete mitochondrial DNA (mtDNA) of the Tylosurus acus melanotus in order to analyse the inheritance and evolutionary relationship of this species. The total length of the mitochondrial genome is 16,723 bp and deposited in the GenBank with accession numbers KU605633. The gene arrangement was similar to other bony fishes which contained 37 genes (13 protein-coding genes, 2 ribosomal RNA and 22 transfer RNAs) and a major non-coding control region. Most genes were encoded on the H-strand, except for the ND6 and 8 tRNA genes, encoding on the L-strand. The mtDNA may provide some important genetic background information for this valuable fish. The nucleotide skewness for the coding strands of T. acus melanotus (GC-skew = −0.21) is biased towards G and the negative GC-skew ranges from -0.53(ATP8) to -0.12(CO2) and the AT-Skew showed more positive varying from −0.17(ND3) to 0.26(ATP6). The phylogenetic analysis demonstrated that T. acus melanotus was clustered together with Ablennes hians, but far away from Cololabis saira which belongs to Beloniformes, Belonidae.