Tylosurus Crocodilus Research Articles

Effect of medium molecular weight chitosan coating on quality of houndfish (Tylosurus crocodilus) during ice storage

Effect of medium molecular weight chitosan coating on quality of houndfish (Tylosurus crocodilus) during ice storage

Morphological and Molecular Study of the Fish Parasitic Crustaceans Cymothoa indica and Mothocya collettei (Isopoda: Cymothoidae), with New Distribution Records

Cymothoidae are parasitic isopods that infest fishes inhabiting marine, brackish, and fresh-water environments. The systematics, distribution, and host specificity of cymothoids is often unknown. In this study, morphological observations and molecular analysis using the COI and 16S rRNA genes were conducted on a juvenile individual of Cymothoa indica infesting the wide-banded hardyhead silverside, Atherinomorus lacunosus, and an ovigerous female of Mothocya collettei infesting the hound needlefish, Tylosurus crocodilus, both collected from Okinawa Island, Japan. This is the first time that these two species of cymothoid have been collected in the Ryukyu Islands, and the juvenile C. indica in particular represents a new northern range limit for its species. That specimen was identified using molecular analysis and showed almost identical morphology to previously reported juveniles, but it differed in the numbers of robust setae on pereopods 6 and 7. The ovigerous female of M. collettei showed a high morphological similarity to M. collettei but had some morphological traits consistent with Mothocya affinis. DNA analysis indicated that these two nominal species of Mothocya are very closely related, and morphological and molecular studies using larger populations of both are needed.

Studi distribusi tertangkapnya ikan pada Soma Tono selama satu siklus bulan

This study aims to determine the distribution of caught fish in "soma tono" and the types of fish caught and how the fish are caught. Soma Tono is classified in gillnets that are rectangular in shape and equipped with buoys, upper ropes, lower ropes, weights and sign buoys. Operation of soma tono fishing gear consists of preparation, net lowering (setting), soaking (soaking) and lifting the net (hauling). The principle of soma tono fishing gear (gillnet) is to wait for fish to be entangled in the body of the net. The method used is a descriptive method, namely managing data obtained when making observations, interviews and documentation. The dominance of fish obtained by bounced fish, the type of fish obtained is the dominance of demersal fish or bottom fish, namely jackfruit seed fish (Upeneus molluccensin), lencam fish (Letrinus lencan), snapper fish (Lutjanus campechanus), lolosi fish (Caesio chrysozona), kuwe fish (Caranx ignobilis), grouper (Epinephelus longispinis), curisi fish (Nemipterus nemaptohorus), sako fish (Tylosurus crocodilus), parrotfish (Scarus rivulatus Valenciennes), puffer fish (Tetraodontidae), sardines (Amblygaster sirm), baronang fish (Siganus) and sea eels (Muraenidae). The results obtained four phases of the moon, namely the 1st quarter moon phase (101.5 kg), the new moon phase (168.7 kg), 2nd quarter moon phase (89 kg) and the full moon phase (63kg).

Population genetics of the hound needlefish Tylosurus crocodilus (Belonidae) indicate high connectivity in Tanzanian coastal waters

ABSTRACT The hound needlefish Tylosurus crocodilus (Belonidae) is a highly demanded fish in the local markets of Tanzania, but the growing coastal population threatens its sustainability. As belonids are highly migratory fishes utilising various parts of the seascape, increased fishing pressure may disrupt connectivity patterns on different spatiotemporal scales and disaggregate populations. Using the COI gene, this study assessed the genetic population structure, connectivity patterns, and historical demography of T. crocodilus collected in seven sites spread along Tanzanian coastal waters. Results showed fourteen haplotypes with low overall nucleotide and haplotype diversity. Pairwise FST comparisons revealed no significant differences among the sampled sites, except for the northernmost site (Tanga) and an island in the south (Songosongo). Analysis of molecular variance (AMOVA) revealed a non-significant genetic structure among populations (FST = 0.01782), suggesting the fishery across Tanzanian waters exploits the same population. Moreover, there was no correlative relationship between genetic and pairwise geographic distances, rejecting the isolation by distance hypothesis. However, neutrality tests and mismatch distribution analysis revealed that recent demographic expansion might exist. Empirical evidence of panmixia suggests high genetic connectivity. In combination with low genetic diversity, management should be directed to actions that prevent genetic diversity loss and the effect of genetic drift on populations.

New records of introduced species in the Mediterranean Sea (April 2023)

This Collective article reports 17 introduced species and 22 new locations for these species in the Mediterranean Sea. The reports are from three different Marine Strategy Framework Directive (MSFD) subregions (Aegean-Levantine Sea, Adriatic Sea and Western Mediterranean Sea) and the Sea of Marmara and cover ten different countries. The goal of consistent and detailed reporting of introduced species is to complement the existing species inventories and serve as a basis for establishing monitoring strategies and other conservation measures. Some of the reports from this article are the first species records for the Mediterranean Sea, namely the green alga Udotea flabellum from the Aegean Sea (Turkey) and the deepbody boarfish Antigonia capros from the Balearic Sea (Spain). In addition, new records of introduced species are included for different seas, namely the moon crab Matuta victor for the Aegean Sea (Greece), the whale shark Rhincodon typus and the lionfish Pterois miles for the Alboran Sea (Spain), the almaco jack Seriola rivoliana for the Tyrrhenian Sea (Italy), and the hound needlefish Tylosurus crocodilus for the Adriatic Sea (Italy). Furthermore, reports on first country records are included: the red alga Colaconema codicola from Slovenia, the nudibranch Melibe viridis from Bosnia and Herzegovina, the lionfish Pterois miles from Montenegro, and the goldstripe sardinella Sardinella gibbosa from Syria, which also represents a second record for the Mediterranean Sea. Furthermore, the occurrence of the scleractinian coral Oculina patagonica was noted in Gulf of Lion (France). Four polychaete species, namely Leodice antennata, Timarete punctata and Branchiomma bairdi, are reported from the vermetid reef habitat and two of them (L. antennata and B. bairdi) are also recorded for the first time in Lebanon. Evidence for established populations of the Asian date mussel Arcuatula senhousia in the Sea of Marmara (Turkey) and the rayed pearl oyster Pinctada radiata around the island of Sardinia (Italy) is provided.

Axinids (Monogenoidea: Mazocraeidea: Microcotylinea) infecting the gill lamellae of some beloniform fishes in the Gulf of Mexico, with descriptions of Axine buccina n. sp. from Hyporhamphus unifasciatus (Ranzani) and Nudaciraxine timucua n. sp. from Strongylura timucu (Walbaum).

Five species of Axinidae (Monogenoidea: Mazocraeidae) were recovered from the gill lamellae of four of six species of needlefishes and halfbeaks examined from the Gulf of Mexico off Florida: Axine buccina n. sp. from a common halfbeak Hyporhamphus unifasciatus (Ranzani); Nudaciraxine gracilis (Linton, 1940) Price, 1962 (minimum prevalence 60%) from the Atlantic needlefish Strongylura marina (Walbaum); Nudaciraxine timucua n. sp. (36%) from the timucu Strongylura timucu (Walbaum); and Axinoides raphidoma Hargis, 1956 (29%) and Chlamydaxine truncata (Hargis, 1956) Unnithan, 1957 (29%) both from the houndfish Tylosurus crocodilus (Péron & LeSueur). The American halfbeak Hyporhamphus meeki Banford & Collette (24 specimens examined) and the redfin needlefish Strongylura notata (Poey) (94 specimens) were uninfected with axinids. The two new axinid species were figured and described. The current status of the Axinidae was explored, which suggested that an objective evaluation of its position within the Monogenoidea is needed.

ANALISIS FILTRAT KONSENTRAT PROTEIN DARI JENIS IKAN YANG BERBEDA

Fish protein concentrate is a food ingredient for human consumption, the way of making it is by separating water and fat in order to get a higher protein content than the original. The fish used for the process of making fish protein concentrate were swordfish (Tylosurus crocodilus), lemuru fish (Sardinella lemuru) and tuna (Euthynnus affinis). In the process of making protein concentrates, the filtrate is still neglected. The process of making fish protein concentrate includes sample preparation, maceration with 85% ethanol solvent for 3 hours, filtering to separate the residue and filtrate, the filtrate is evaporated using an oven at 45°C for 24 hours. The test parameters in this study included yield calculation, phytochemical testing, antioxidant activity testing and soluble protein content testing. Based on the results of the research conducted, the highest yield was found in P3 with a value of 5.33%. In the phytochemical test results P1, P2 and P3 contained alkaloids, saponins and ninhydrin. The results of testing the antioxidant activity of the three types of fish have potential as antioxidant compounds. The antioxidant activity at P1 has an IC50 value of 22.57 ppm, P2 has an IC50 value of 19.20 ppm and at P3 has an IC50 value of 15.09 ppm. In the test results, the highest soluble protein content was found in P2 with a value of 0.166 mg/mL followed by P1 having a value of 0.69 mg/ml and the lowest soluble protein content was found in P3 with a value of 0.61 mg/ml.

KARAKTERISTIK OTAK-OTAK TULANG IKAN TODAK (Tylosurus crocodilus) DENGAN PENERAPAN TEKNOLOGI MODERN

Fishbone otak-otak is one of the processing the results of fisheries diversification. Fishbone otak-otak have a weakness, the bones in this product cannot be consumed, besides that the bones can cause mouth irritation, this is the application of modern technology is involved in overcoming weaknesses in consumption fishbone otak-otak. One of the modern technology namely with presto technology. The purpose of this research find outphysical (Organoleptic, Rendemen) and chemical (Proximate, Calcium, Bone Hardness) on the characteristics of the fishbone otak-otak swordfish (Tylosurus crocodilus). Method This uses a completely randomized design (CRD), consisting of 3 treatments, namely during 1 hour (T1), 1.5 hours (T2), 2 hours (T3) and 3 replications at a temperature of 115-120 oC. Result the best organoleptic testing is 1.5 hours treatment gave an average appearance value (2.47%), Odor (2.60%), Taste (2.60%) and Texture (2.50%). The results of the yield analysis were 1 hour (60%) 1.5 hours (59%) 2 hours (58%). Proximate analysis results based on treatment best get scorerate-ratewater content (54.44%) ash content (19.21%) fat content (5.64%) protein content (9.70%) carbohydrate content (22.04%). The highest result of calcium analysis is 6594.11 mg/ 100 g. The results of the analysis of bone hardness were 1061.75 g.

Two New Species of Philometrid Nematodes (Philometridae), Barracudia Notabilis n. sp. and Philometra Consimilis n. sp., from the Ovary of the Hound Needlefish Tylosurus Crocodilus (Belonidae) Off Florida, USA.

SummaryTwo new species of philometrid nematodes (Philometridae), Barracudia notabilis n. sp. and Philometra consimilis n. sp., are described from males found in the ovary of the hound needlefish Tylosurus crocodilus (Péron et Lesueur) (Belonidae) from off the Atlantic coast of Florida, USA. Both species are described and illustrated based on light and scanning electron microscopical examinations. Barracudia notabilis n. sp., the first representative of this genus from fishes in the Atlantic Ocean, can be differentiated from other congeners by the body length of the male (2.69 mm), the length of the gubernaculum (57 μm) and spicules (81 μm), and by the shape of the gubernaculum. Philometra consimilis n. sp. differs from all congeners mainly in the unique structure of the distal tip of the gubernaculum (bearing two smooth dorsal barbs) and the species is also characterized by the length of spicules (111 μm) and the length of the gubernaculum (84 μm). Further studies are needed to discover and describe so far unknown gravid females of Barracudia spp.

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.

Hydroxyapatite Extracted from Fish Bone Wastes by Heat Treatment

The present work demonstrates a low-cost route to produce hydroxyapatite (HAp) from fish bones (natural source) by a simple heat-treatment process. The produced HAp was characterized by X-ray Diffraction (XRD) and Fourier Transform Infra-Red (FTIR). Energy Dispersive X-ray (EDX) analysis obtained elemental composition that confirmed the presence of Ca and P; then the Ca/P mole ratio was calculated. XRD analysis from Chanos chanos and Calarias batracus bone has produced the diffraction peaks at 31.8°, 32.1°, and 32.9° that corresponded to the HAp phase. The presence of functional groups, PO43‒ and OH‒, has been confirmed by FTIR spectra that arecharacteristics of HAp. EDX analysis has shown that the Ca/P mole ratio was similar to the Ca/P mole ratio of the HAp’s stoichiometry (1.66). But actually, not all fish bones can produce pure HAp after the heat-treatment process, such as Tylosurus crocodilus bone. Based on XRD analysis from the main diffraction peak form is a β-TCP phase

Role of women and coastal livelihood in the small-scale fisheries (SSF) of Lupon and Governor Generoso, Davao Oriental

In the small-scale fisheries, women have played a significant role, upending their traditional role of domestic activities. In this study, we shed light on various roles of women in their coastal communities in Lupon and Governor Generoso, Davao Oriental, and how their different activities revolve around the fisheries sector. A total of 88 women were randomly interviewed using semi-structured questionnaires in their homes and fish landing sites. Women participated in the fisheries between the ages of 35 and 55 years; in terms of educational attainment, they were primarily high school level and mostly were Cebuano. About 50% of them have access to credit, which they use for small businesses, purchasing fishing equipment, and the needs of their families. Women were involved in activities such as pre-fishing, fishing offshore, post-fishing, and fishing-related activities. Women were also engaged in collecting shells such as latticed top shells (Tectus fenestratus), little bear conch (Canarium urceus), singed cones (Conus consors), and blood clams (Anadara antiquata) at low tide. Their husbands were mainly engaged in fishing, where their common fish catch are flyingfish (Cheilopogon furcatus), roundscad (Decapterus macrosoma), dolphin fish (Coryphaena hippurus), skipjack tuna (Katsuwonus pelamis), yellowfin tuna (Thunnus albacares), bigeye scad (Selar crumenophthalmus), needlefish (Tylosurus crocodilus), and common squid (Sepioteuthis lessoniana). Overall, the women in the coastal communities played a significant role in the fisheries. Further, there is a need to empower them by providing loans and credit facilities, developing their capabilities, improving their livelihood, and enhancing their socioeconomic status.

Role of women and coastal livelihood in the small-scale fisheries (SSF) of Lupon and Governor Generoso, Davao Oriental

In the small-scale fisheries, women have played a significant role, upending their traditional role of domestic activities. In this study, we shed light on various roles of women in their coastal communities in Lupon and Governor Generoso, Davao Oriental, and how their different activities revolve around the fisheries sector. A total of 88 women were randomly interviewed using semi-structured questionnaires in their homes and fish landing sites. Women participated in the fisheries between the ages of 35 and 55 years; in terms of educational attainment, they were primarily high school level and mostly were Cebuano. About 50% of them have access to credit, which they use for small businesses, purchasing fishing equipment, and the needs of their families. Women were involved in activities such as pre-fishing, fishing offshore, post-fishing, and fishing-related activities. Women were also engaged in collecting shells such as latticed top shells (Tectus fenestratus), little bear conch (Canarium urceus), singed cones (Conus consors), and blood clams (Anadara antiquata) at low tide. Their husbands were mainly engaged in fishing, where their common fish catch are flyingfish (Cheilopogon furcatus), roundscad (Decapterus macrosoma), dolphin fish (Coryphaena hippurus), skipjack tuna (Katsuwonus pelamis), yellowfin tuna (Thunnus albacares), bigeye scad (Selar crumenophthalmus), needlefish (Tylosurus crocodilus), and common squid (Sepioteuthis lessoniana). Overall, the women in the coastal communities played a significant role in the fisheries. Further, there is a need to empower them by providing loans and credit facilities, developing their capabilities, improving their livelihood, and enhancing their socioeconomic status.

Two new species of Prosorhynchoides (Digenea: Bucephalidae) from Tylosurus crocodilus (Belonidae) from the great barrier reef and French Polynesia

We surveyed 14 individuals of Tylosurus crocodilus Péron & Lesueur 1821 (Belonidae) collected from the waters around Lizard Island and Heron Island, Great Barrier Reef, Queensland, Australia, and the waters around Moorea, French Polynesia. We describe two new species of bucephaline trematodes from them, Prosorhynchoides galaktionovi n. sp. and P. kohnae n. sp. They are morphologically distinct from existing Prosorhynchoides spp., with molecular data from 28S and ITS-2 ribosomal DNA, as well as cox1 mitochondrial DNA, further supporting our morphological findings. Neither species has been observed in other belonid fishes. The new species fall into the clade of species of Prosorhynchoides from belonids previously identified in Australian waters. These findings strengthen the observation that groups of bucephaline species have radiated, at least in part, in tight association with host taxa. There are now five species of Prosorhynchoides known from two belonid species in Australian waters. We, therefore, predict further richness in the nine other belonid species present.

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.

Measuring the specific concentration of the radioactive isotopes of 40K, 137Cs and (224Ra, 226Ra, 228Ra)

The specific concentration of radioisotopes of Potassium 40K; Cesium 137Cs and Radium (224Ra ,226Ra, 228Ra) have been identified for soil, sediment, fish samples (Liza abu, Liza klunzingeri, Brachirus orientalius, Tylosurus crocodilus, Cyprinus carpio and Acanthopagrus arabicus) and kladophora as well as snails in the stations: Qurmat Ali; Al sadir Teaching Hospital; Umm Qasr Port and and Arabian Gulf 1 in 2016. The present study aims to detect the impact of both Chernobyl reactor explosion, Fokushima reactor destruction and the oil industries in the study region environments. The results of the soil and sediment analysis showed that there is an impact of Chernobyl accident. There are observed concentrations for the 137Cs; in addition to the effect of the oil industries in the soil, sediments, and Acanthopagrus arabicus fish and Kladophora crusbate plant. This was proved by measuring the concentrations of Radium isotopes in the amounts above the allowable rates globally and locally. The results of the current study showed that the rates of Potassium 40 were the most prominent in fish samples and the Kladophora crusbate plant, which represents the predominant radiation activity and it is within the permitted natural range. The results of this study can be considered as a basis for monitoring of the future changes.

Prevalence of cymothoid isopods (Crustacea, Isopoda) and proximate analysis of parasites and their host fishes, Southeastern India.

Cymothoid isopods (Crustacea, Isopoda) are considered as potential threat to the health of different fish species. In order to evaluate the prevalence and proximate analysis of Cymothoid isopods and its host, an investigation was carried out fish species belonging to families Hemiramphidae and Belonidae in the Palk Bay region, Southeastern India. A total of 1265 individuals of teleost fish belonging to family Hemiramphidae species, Hemiramphus far (462), H. archipelagicus (78), and H. lutkie (277) and another family Belonidae species, Tylosurus crocodilus (448), were examined for cymothoid ectoparasitic infestation. Prevalence in H. far was the highest (39%) for the cymothoid Mothocys plagulophora, while T. crocodilus was most infested (13%) with Mothocys renardi, H. far and H. lutkie were not infested by M. renardi while T. crocodilus was not infested by M. plagulophora. Proximate analysis showed reduced level of protein in parasite infested fish compared with non-infested individuals. However, carbohydrate and lipid concentrations were lower in infested fish than non-infested individuals. Proximate analysis values in the two parasites of Mothocys species were similar, and these values were comparable to those unaffected fish species indicating that parasites were well nourished. The proximate analysis of isopod parasite M. plagulophora showed 21.6 ± 7.7, 1.26 ± 0.05, 5.49 ± 1.06% of protein, carbohydrate and lipid respectively, and in M. renardi, 21.09 ± 6.6, 1.32 ± 0.12, 5.83 ± 0.72% of protein, carbohydrate and lipid respectively. Cadmium levels were similar between affected and non-affected fish individuals and among species. The Pb levels were comparable among all T. crocodilus individuals, but the levels of Cd not showed much variation between affected and unaffected individuals in all four fish species.

Family Belonidae from the Suez Canal, Egypt: Age, growth, mortality, exploitation rate and reproductive biology

This is the first attempt to study the biological characteristics and basic population parameters of two important Belonidae species, Tylosurus acus and Tylosurus crocodilus from the Suez Canal. The length– weight relationship was estimated as W = 0.0005TL3.26 for T. acus and W = 0.0007TL3.21 for T. crocodilus. The growth parameters of T. acus were computed as L∞ = 79.85 cm, k = 0.44 year–1, t0 = –0.58 years, while the annual total, natural and fishing mortality were 1.70, 0.72 and 0.98 respectively with an exploitation rate of 0.58. While in T. crocodilus the VBGPs were L∞ = 113.0 cm, k = 0.30 year–1, t0 = –0.46 years, the annual total, natural and fishing mortality were 1.27, 0.51 and 0.76 respectively with an exploitation rate of 0.60. The female's length at first maturity of T. acus was estimated to be 47.3 cm and 51.7 cm for T. crocodilus. Monthly variations in Gonado-somatic index revealed that the spawning season of the two species takes place in spring. Results of exploitation rate indicated that the T. acus and T. crocodilus are fully exploited.