A Novel Bis-Trifluoromethylated Compound Demonstrates High Efficacy as a Nematicide Against Root-Knot Nematodes on Pistachio, Supported by Docking Studies.

Three novel trifluoromethylated compounds were designed and synthesized by reacting trifluoroacetimidoyl chloride derivatives with acetamidine hydrochloride or thiourea in the presence of potassium carbonate or sodium hydrogen carbonate as a base. In vitro and in vivo assays demonstrated the efficacy of the tested compounds in controlling root-knot nematode disease on pistachio rootstocks caused by Meloidogyne incognita. Bis-trifluoromethylated derivatives, namely N,N''-thiocarbonylbis(N'-(3,4-dimethylphenyl)-2,2,2-trifluoroacetimidamide) (compound A1), showed high efficacy as novel and promising nematicides, achieving up to 78.28% control at a concentration of 0.042 mg/liter. This effect is attributed to four methyl and two trifluoromethyl groups. In the pre-inoculation application of compound A1, all three concentrations (0.033, 0.037, and 0.042 mg/liter, and Velum) exhibited a higher level of control, with 83.79, 87.46, and 80.73% control, respectively. In the microplot trials, compound A1 effectively reduced population levels of M. incognita and enhanced plant growth at a concentration of 0.037 mg/liter. This suggests that compound A1 has the potential to inhibit hedgehog protein and could be utilized to prevent the progression of root-knot disease. Furthermore, the molecular docking results revealed that compounds A1 and A3 interact with specific amino acid residues (Gln60, Asp530, Glu70, Arg520, and Thr510) located in the active site of hedgehog protein. Based on the experimental findings of this study, compound A1 shows promise as a lead compound for future investigations.

A new species of the genus Paurodontella Husain & Khan, 1968 (Nematoda: Hexatylina, Sphaerularioidea) with its molecular phylogenetic study.

A new species of the genus Paurodontella, Paurodontella minora n. sp., collected from Alborz Province, Iran, is described and illustrated based on morphological and molecular characters. The new species is characterized by its body length of 393 (350-438) µm and 380 (n = 1) µm in female and male, respectively, 6-7 incisures in lateral field, lip region annulated and continuous with body contour, and total stylet 6.1 (5.5-7.0) µm long. Basal pharyngeal bulb with small posterior extension projecting reaching to the intestine. Excretory pore situated at the level of basal pharyngeal bulb region, no post-uterine sac, conical tail, narrowing to a rounded tip, and rare male with slender tylenchoid spicules and adanal bursa. The new species comes close in morphology and morphometrics to four known species of the genus, namely Paurodontella asymmetrica, Paurodontella balochistanica, Paurodontella densa and Paurodontella niger. In molecular phylogenetic analyses using D2-D3 expansion segments of the large subunit rDNA gene sequence, P. minora n. sp. formed a major clade with species of the genera in the family Sphaerulariidae (Paurodontella, Paurodontoides, Veleshkinema and Sphaerularia) and a sister relation with the members in the families Neotylenchidae and Anguinidae with the same clade support values in Bayesian inference.

Basilaphelenchus hyrcanus n. sp. (Rhabditida: Tylaphelenchinae) associated with bark of a beech tree (Fagus orientalis Lipsky) from northern Iran.

Basilaphelenchus hyrcanus n. sp., the sixth species of the newly established genus was isolated during a nematode survey associated with bark samples of beech tree in northern Iran, which differs from the other species by body size, stylet length, metacorpus structure, and tail characters of both genders. The new species is also characterized by elevated cephalic region with sclerotised vestibule, posteriorly directed stylet knobs, well-developed metacorpus filling corresponding body region, position of excretory pore at the level of base of metacarpus, length of post uterine sac by 38-60 µm long, conoid elongate tail by sharp to finely rounded tip in female. Based upon the morphological characteristics and phylogenetic analyses of partial 18 S and D2-D3 28 S rDNA segments, the new species mostly resembles B. magnabulbus. However, B. hyrcanus n. sp. is clearly different from this species by having a longer stylet, different position of the excretory pore, a different male tail tip characters and 4.4 and 13.2% sequence divergences in 18 S and D2-D3 28 S, respectively.

Description of Deladenus gilanica n. sp. (Hexatylina: Neotylenchidae) isolated from wood of black pine in Northern Iran.

A new species of the genus Deladenus, D. gilanica n. sp. collected from Siahkal forests of Northern Iran, is described and illustrated. The new species is characterized by its 314 to 422-µm-long body, eight incisures in the lateral field, 7.5 to 8.0-µm-long stylet, position of the excretory pore, at the level of the hemizonid, both posterior to the nerve ring 61 to 76 µm from the anterior end, and conical tail with pointed tip. Based on morphology and morphometrics, the new species can be compared with eight known species of the genus: D. aridus, D. durus, D. obesus, D. oryzae, D. processus, D. wilsoni, D. proximus, and D. posteroporus. Evolutionary relationships of the new species with other Deladenus species were assessed with sequences of the D2 to D3 expansion regions of 28S rRNA and partial 18S rRNA gene. The phylogenetic analysis showed that D. gilanica n. sp. is genetically distinct from other included species. Deladenus gilanica n. sp. is a member of the D. siricidicola species complex and close to D. canii, D. nitobei, and D. siricidicola. Typologically, these species share the relative position of the excretory pore to the hemizonid.A new species of the genus Deladenus, D. gilanica n. sp. collected from Siahkal forests of Northern Iran, is described and illustrated. The new species is characterized by its 314 to 422-µm-long body, eight incisures in the lateral field, 7.5 to 8.0-µm-long stylet, position of the excretory pore, at the level of the hemizonid, both posterior to the nerve ring 61 to 76 µm from the anterior end, and conical tail with pointed tip. Based on morphology and morphometrics, the new species can be compared with eight known species of the genus: D. aridus, D. durus, D. obesus, D. oryzae, D. processus, D. wilsoni, D. proximus, and D. posteroporus. Evolutionary relationships of the new species with other Deladenus species were assessed with sequences of the D2 to D3 expansion regions of 28S rRNA and partial 18S rRNA gene. The phylogenetic analysis showed that D. gilanica n. sp. is genetically distinct from other included species. Deladenus gilanica n. sp. is a member of the D. siricidicola species complex and close to D. canii, D. nitobei, and D. siricidicola. Typologically, these species share the relative position of the excretory pore to the hemizonid.

Description of Malenchus gilanensis n. sp. from Iran.

Malenchus gilanensis n. sp. is described and illustrated from wood samples from Iran. Morphologically, this new species is characterized by very small body size, cuticle with narrow annuli (0.8-0.9 µm wide at mid-body), lateral field with two lines, originating at the level of the median pharyngeal bulb valve, straight amphidial apertures (similar to members of the subgenus Telomalenchus), sunken vulva with large lateral flaps, prophasmids located almost level with to 9 annuli posterior to the vulva in females, and undeveloped adanal bursa which can be considered as an outgrowth of the lateral field in males. Malenchus gilanensis n. sp. resembles members of subgenus Telomalenchus due to the straight amphidial apertures, prophasmid position and large lateral flaps, but it differs by having two lines in the lateral fields. This new species is morphologically similar to five known species of the subgenus Malenchus: M. acarayensis, M. bryanti, M. parvus, M. nanellus and M. truncatus. The new species can be distinguished from them and other species in the subgenus by having straight amphidial apertures, two lines in the lateral fields, position of prophasmids, and having a very small and undeveloped bursa.

Molecular and morphological characterization of Paurodontella composticola n. sp. (Nematoda: Hexatylina, Sphaerulariidae) from Iran.

A new species of the genus Paurodontella, P. composticola n. sp., collected from Nazar Abad City, Alborz Province, Iran, is described and illustrated. The new species has a body length of 803-1053 µâ€Šm (females n = 10) and 620 and 739 µâ€Šm (males n = 2). The cuticle is weakly annulated with four lateral lines. Cephalic region is annulated and continuous with body contour. The stylet is 8.0 to 9.0 µâ€Šm long with asymmetrical knobs. Esophageal basal bulb is present with a small posterior extension projecting into the intestine. Excretory pore is situated at the level of esophageal basal bulb region. Post-uterine sac is 5 to 8 µâ€Šm long and uterus is without diverticulum. Tails of both sexes are similar, short and sub-cylindrical. Males have 24 to 25 µâ€Šm long bursa leptoderan and spicules 24 or 25 µm long. A non-branching oviduct is present to form a uterine diverticulum; the new species is closely related to five known species of the genus, namely P. asymmetrica, P. balochistanica, P. densa, P. iranica and P. niger. It most closely resembles P. iranica, but differs from it morphologically by a shorter stem-like extension projecting into lumen of intestine and male with sub-cylindrical tail vs conoid. In addition to morphological comparisons, the molecular phylogenetic analyses based on 733 bp of the partial sequence of 28S D2/D3 expansion segments of the large subunit rDNA gene (LSU) revealed this as a new species.A new species of the genus Paurodontella, P. composticola n. sp., collected from Nazar Abad City, Alborz Province, Iran, is described and illustrated. The new species has a body length of 803­1053 µâ€Šm (females n = 10) and 620 and 739 µâ€Šm (males n = 2). The cuticle is weakly annulated with four lateral lines. Cephalic region is annulated and continuous with body contour. The stylet is 8.0 to 9.0 µâ€Šm long with asymmetrical knobs. Esophageal basal bulb is present with a small posterior extension projecting into the intestine. Excretory pore is situated at the level of esophageal basal bulb region. Post-uterine sac is 5 to 8 µâ€Šm long and uterus is without diverticulum. Tails of both sexes are similar, short and sub-cylindrical. Males have 24 to 25 µâ€Šm long bursa leptoderan and spicules 24 or 25 µm long. A non-branching oviduct is present to form a uterine diverticulum; the new species is closely related to five known species of the genus, namely P. asymmetrica, P. balochistanica, P. densa, P. iranica and P. niger. It most closely resembles P. iranica, but differs from it morphologically by a shorter stem-like extension projecting into lumen of intestine and male with sub-cylindrical tail vs conoid. In addition to morphological comparisons, the molecular phylogenetic analyses based on 733 bp of the partial sequence of 28S D2/D3 expansion segments of the large subunit rDNA gene (LSU) revealed this as a new species.

Description of Tylencholaimus discus sp. n. (Nematoda, Dorylaimida, Tylencholaimidae) from Iran.

A new species of the genus Tylencholaimus, collected in natural areas of Iran, is described and illustrated, including SEM observations. Tylencholaimus discus sp. n. is characterized by its 0.65-0.76 mm long body, lip region offset by weak constriction and 7-7.5 µm broad with a conspicuous perioral disc, odontostyle 6-7 µm long, odontophore 9-10.5 µm long and visibly flanged rather than knobbed, neck 230-259 µm long with anterior region weakly muscular and basal expansion 98-125 µm long or occupying 42-49% of total neck length, female genital system mono-prodelphic, posterior branch reduced to a uterine sac 2-20 µm long or much shorter (0.1-0.6 times) than body diameter but very occasionally consisting of uterus, sphincter and a small terminal mass all together measuring 35-40 µm long, V = 65-74, tail short and rounded (13-17 µm, c = 41-57, c' = 0.6-0.8), and male unknown.

Nothotylenchus andrassy n. sp. (Nematoda: Anguinidae) from Northern Iran.

Nothotylenchus andrassy n. sp. is described and illustrated from moss ( Sphagnum sp.) based on morphology and molecular analyses. Morphologically, this new species is characterized by a medium body size, six incisures in the lateral fields, and a delicate stylet (8-9 µm long) with clearly defined knobs. Pharynx with fusiform, valveless, non-muscular and sometimes indistinct median bulb. Basal pharyngeal bulb elongated and offset from the intestine; a long post-vulval uterine sac (55% of vulva to anus distance); and elongate, conical tail with pointed tip. Nothotylenchus andrassy n. sp. is morphologically similar to five known species of the genus, namely Nothotylenchus geraerti , Nothotylenchus medians , Nothotylenchus affinis , Nothotylenchus buckleyi , and Nothotylenchus persicus . The results of molecular analysis of rRNA gene sequences, including the D2-D3 expansion region of 28S rRNA, internal transcribed spacer (ITS) rRNA and partial 18S rRNA gene are provide for the new species.

Description of a New Anguinid Nematode, Nothotylenchus phoenixae n. sp. (Nematoda: Anguinidae) Associated with Palm Date Trees and Its Phylogenetic Relations within the Family Anguinidae.

Nothotylenchus phoenixae n. sp. is described and illustrated from soil samples of palm trees in Kermanshah Province, western Iran. The new species is characterized by a body length of 784 (663 to 925) µm in females and 677 to 715 µm in males; a delicate stylet 6 (5 to 7) µm long and six lines in the lateral field; median bulb of pharynx fusiform, nonmuscular, and nonvalvate; isthmus elongate, slender ending to a pyriform basal pharyngeal bulb not overlapping intestine; postvulval uterine sac well developed, 15 (14 to 17) µm long, female tail elongate-conoid with pointed terminus; and male with adanal bursa and spicules 21 to 22 µm long (n = 2). The new species comes close in morphology and morphometrics to five known species of the genus, namely N. affinis, N. hexaglyphus, N. persicus, N. taylori, and N. uniformis. Molecular analyses of the partial 18S, D2/D3 expansion segments of the partial 28S and internal transcribed spacer (ITS) revealed this as a new species. The sequences of the partial 18S and 28S D2/D3 regions confirmed the close phylogenetic relationship between N. phoenixae n. sp. and other anguinids, but Nothotylenchus is clearly separated from Ditylenchus species and should be considered as a valid genus.

Description of Aphelenchoides macrospica n. sp. (Nematoda: Aphelenchoididae) from Northwestern Iran.

Aphelenchoides macrospica n. sp. is described and illustrated from the West Azerbayjan province, northwestern Iran. The new species is characterized by its body length of 807 to 963 µm (males) and 792 to 1,094 µm (females), offset cephalic region, lateral fields with four incisures, long stylet with 15 to 16 µm length, and excretory pore situated opposite or behind the nerve ring. Pharyngeal glands overlapping intestine dorsally and extending for 90 to 121 µm, tail terminus mucronate in both sexes. Vagina directed anteriad, and spicules are relatively large (27-32 µm) with well-developed broadly rounded apex and condylus. The new species comes close to seven known species of the genus namely A. arcticus, A. blastophthorus, A. haguei, A. huntensis, A. lucknowensis, A. parasaprophilus, and A. xui, but it differs from them by the body size, stylet length, size of spicules, and length of postvulval uterine sac. The results of phylogenetic analyses based on sequences of D2-D3 expansion region of 28S and 18S rDNA, confirmed its status as a new species.

Morphological characterisation of a new and two known species of Ditylenchus Filipjev, 1936 (Nematoda: Anguinidae) from Iran.

Ditylenchus sturhani sp. n. from the rhizosphere of grasses in East Azarbaijan province, Northwestern Iran, is described and illustrated. The new species is characterised by a straight to slightly arcuate body 656-865 µm in length, presence of four incisures in each lateral field, slender stylet 10-12 µm in length, pharyngeal basal bulb offset or slightly overlapping the intestine, post-uterine sac 1.0-1.9 vulval body diameter long and conical tail with finely rounded terminus. Differences with closely related species including D. solani, D. ausafi, D. angustus, D. dipsaci, D. drepanocercus, D. obesus and D. gallaeformans are discussed. In addition, Iranian populations of two known species, D. valveus and D. virtudesae, are morphologically characterised.

Description of two new species of Seinura Fuchs, 1931 (Nematoda: Aphelenchoididae) from Iran.

Two new species of Seinura are described and illustrated using both morphological and molecular characters. Seinura persica n. sp. is characterized by having females with a distinct cephalic region, stylet 19.5 (18-20) µm long, four incisures in the lateral fields, position of excretory pore anterior to the base of metacorpus, post-uterine sac 54.8 (50-60) µm long, and an elongate-conoid tail with a shallow depression on the dorsal side ending in a sharply pointed tip. Males have body length of 467 and 592 µm, spicules 15 and 16 µm long with a prominent triangular-shaped rostrum, developed condylus and no cucullus. Seinura hyrcania n. sp. is characterized by having an offset lip region, stylet 21.5 (18-24) µm long, three incisures in the lateral fields, excretory pore anterior to the base of the metacorpus, post-uterine sac 19 (12-25) µm long and conical tail ending in a filiform terminus. Morphological and morphometric diagnostic characters together with molecular data based on partial sequences of SSU and LSU of the ribosomal DNA gene are provided for these new species.

Paurodontella parapitica n. sp. (Nematoda: Hexatylina, Sphaerularioidea) from Kermanshah Province, Western Iran.

Paurodontella parapitica n. sp., collected from the rhizosphere of an apple tree in Kermanshah province, western Iran, is described. The new species is characterized by a body length of 505 to 723 µm (females) and 480 to 600 µm (males), lip region continuous by depression; 7 to 8 µm broad, 3 to 4 µm high, stylet length 7 to 9 µm or 1 to 1.3 times the lip region diameter, short postuterine sac of 4 to 6 µm long, lateral fields with five to six incisures; outer incisures crenated and inner incisures weakly crenated, excretory pore situated 90 to 100 µm from anterior end; functional males common in the population, with spicules 24 to 26 µm long. Tail of both sexes similar, almost straight and elongate-conoid. The new species resembles in morphology and morphometrics to four known species of the genus, namely P. apitica, P. minuta, P. myceliophaga, and P. sohailai. The results of phylogenetic analyses based on sequences of D2/D3 expansion region of 28S rRNA gene revealed this genus is polyphyletic in four different clades in Tylenchid.

Description of Cryptaphelenchus iranicus n. sp. (Nematoda: Ektaphelenchinae) recovered from bark samples of Pinus nigra from Iran.

Cryptaphelenchus iranicus n. sp., recovered from bark and wood samples of a weakened Pinus nigra in Kermanshah Province, western Iran, is described. The new species has females with body length of 250-330 µm and males 230-275 µm long, lip region set-off from body contour, 7-8 µm long stylet with small basal swellings, excretory pore located at 1.5-2.0 body diam. posterior to median bulb, post-vulval uterine sac short, 7-10 µm long and conical female posterior body end (tail) ending to a pointed tip. Males of the new species have seven (1+2+2+2) caudal papillae and a short mucro at tail tip. Based on morphological characters, the new species is close to C. cirrus, C. latus and C. leptocaudus. Phylogenetic analyses using the D2/D3 fragment of 28S rDNA show the new species forming a clade with other Cryptaphelenchus species with maximal (1.00) Bayesian posterior probability (BPP) in Bayesian inference and 100% bootstrap value (BS) in the maximum likelihood method. The Cryptaphelenchus clade forms a monophyletic group with members of subfamily Ektaphelenchinae.

Molecular and Morphological Characterization of Aphelenchoides fuchsi sp. n. (Nematoda: Aphelenchoididae) Isolated from Pinus eldarica in Western Iran.

Aphelenchoides fuchsi sp. n. is described and illustrated from bark and wood samples of a weakened Mondell pine in Kermanshah Province, western Iran. The new species has body length of 332 to 400 µm (females) and 365 to 395 µm (males). Lip region set off from body contour. The cuticle is weakly annulated, and there are four lines in the lateral field. The stylet is 8 to 10 µm long and has small basal swellings. The excretory pore is located ca one body diam. posterior to metacorpus valve or 51 to 62 µm from the head. The postuterine sac well developed (60-90 µm). Spicules are relatively short (15-16 µm in dorsal limb) with apex and rostrum rounded, well developed, and the end of the dorsal limb clearly curved ventrad like a hook. The male tail has usual three pairs of caudal papillae (2+2+2) and a well-developed mucro. The female tail is conical, terminating in a complicated step-like projection, usually with many tiny nodular protuberances. The new species belongs to the Group 2 sensu Shahina, category of Aphelenchoides species. Phylogenetic analysis based on small subunit (SSU) and partial large subunit (LSU) sequences of rRNA supported the morphological results.

Rotylenchus sardashtensis n. sp., a monosexual species from Iran, with molecular identification and detailed morphological observations on an Iranian population of Rotylenchus cypriensis Antoniou, 1980 (Nematoda: Rhabditida: Hoplolaimidae).

Rotylenchus sardashtensis n. sp., a new monosexual species is described and illustrated based on morphological, morphometric and molecular studies. Rotylenchus sardashtensis n. sp. appears close morphologically and molecularly to eight known species of the genus, i.e. R. buxophilus Golden, 1956, R. eximius Siddiqi, 1964, R. breviglans Sher, 1965, R. cypriensis Antoniou, 1980, R. pakistanensis Maqbool & Shahina, 1986, R. vitis Cantalapiedra-Navarrete, Liébanas, Archidona-Yuste, Palomares-Rius & Castillo, 2012, R. paravitis Cantalapiedra-Navarrete, Navas-Cortés, Liébanas, Vovlas, Subbotin, Palomares-Rius & Castillo, 2013 and R. dalikhaniensis Aliramaji, Pourjam, Álvarez-Ortega, Pedram & Atighi, 2015 from which the morphological differences are discussed. The new species is characterised mainly in having a hemispherical and well set off lip region with 3-4 annuli under light microscopy and irregular cob-like appearance under scanning electron microscopy (SEM), a stylet 26-30 µm long, a vulva located at 61-77% of body length with double epiptygma, rounded tail with 2-4 annuli and ventral mucron at its tip. Morphologically, R. sardashtensis n. sp. could be distinguished from all similar species within the genus by its matrix code as follows: A3, B1, C1, D4, E1, F2, G2, H5, I2, J2, K1. Rotylenchus cypriensis collected from the rhizosphere of Prunus sp. in Gilangharb region is characterised with its morphological and molecular data. Phylogenetic analyses based on sequences of the D2-D3 expansion region of the 28S rRNA gene and the ITS1 fragment revealed the relationships of both species examined in present study and other species of the genus Rotylenchus Filipjev, 1936 and the family Hoplolaimidae Filipjev, 1934 included in analyses.

Molecular and morphological characterization of Veleshkinema iranicum n. gen., n. sp. (Nematoda: Hexatylina, Sphaerularioidea) from Iran.

Veleshkinema  iranicum n. gen., n. sp. is described and illustrated based on morphological, morphometric and molecular characters. The new genus is characterized by having slender females and males, stylet with asymmetrical knobs, dorsal gland orifice just posterior to subventral knob, lip region with flattened apex and eight sectors, pharynx with a non-muscular and non-valvular median bulb, pharyngeal glands slightly overlapping intestine dorsally, visible cellular cardia, female with a single gonad having a quadricolumellate crustaformeria with 8-10 cells in each column, no postvulval uterine sac and rounded and offset spermatheca containing spheroid sperm cells, males with arcuate tylenchoid spicules and subterminal bursa. The new genus is morphologically compared with four genera: Abursanema, Deladenus, Prothallonema and Sphaerularia. Molecular phylogenetic studies of the new genus using 808 bp partial sequences of SSU ribosomal RNA gene placed the new genus in a clade with Sphaerularia spp. In phylogenetic analyses using 756 bp partial sequences of the 28S ribosomal RNA gene (D2-D3 segments), the new genus formed a monophyletic group with Abursanema iranicum and Sphaerularia spp.

Morphological and molecular characterization of Tylencholaimellus persicus sp. n. (Dorylaimida: Tylencholaimellidae) from Iran.

Tylencholaimellus persicus sp. n. is described and illustrated based on morphological and molecular characters. The new species is characterized by its 613-885 µm long body, expanded lip region separated from body contour by a sharp constriction, forming a large disk-like structure, odontostyle and odontophore respectively 12-14 and 6.5-8.0 µm long, female genital system mono-opisthodelphic with relatively long anterior uterine sac (AUS; 50-80 µm in length), position of vulva relative to the body length (V = 36.5-41.5), broadly rounded tail, abundant males in population with 22-25 µm long spicules and one ventromedian copulatory supplement. The new species is compared with five known species of the genus that have a perioral disc, rounded tail and AUS: T. coronatus, T. incertus, T. montanus, T. ozarkensis and T. projectus. Compared to these five species, the new species has an expanded lip region separated from body contour by a sharp constriction, but can further be separated by a combination of morphological and morphometric characters such as odontostyle length, tail shape, differences in ratios c´ and V and male characters. Because of having similar general morphology, the new species was also compared with a species of genus Margollus, M. bokanicus, and the differences between the two species are discussed. In addition to morphological and morphometric data, molecular phylogenetic analyses were performed using partial sequences of the 18S SSU and 28S LSU D2/D3 rDNA segments, in which the new species forms a clade with four species/isolates of Tylencholaimellus in the SSU tree and one isolate of Tylencholaimus in the LSU tree using Bayesian inference (BI).

Effect of sodium alginate coating enriched with horsemint (Mentha longifolia) essential oil on the quality of bighead carp fillets during storage at 4°C.

Effect of sodium alginate coating enriched with horsemint essential oil (HEO) on the quality of bighead carp (Aristichthys nobilis) fillets at refrigeration temperature (4 ± 1°C) was studied. Bighead carp fillets were coated with neat sodium alginate (SA) and sodium alginate containing 0.5 and 1% v/v of HEO and their quality changes in terms of total volatile basic nitrogen (TVB-N), peroxide value (PV), thiobarbituric acid (TBA), and microbial counts were investigated. SA coating enriched with the essential oil could reduce the spoilage of the fillets and extend their shelf-life. Samples treated with SA-containing HEO showed significantly (P < 0.05) lower TVB-N content and lipid oxidation, as reflected by lower PV, FFA and TBA values during the storage period compared with the SA and control. The treatment also reduced the degree of microbial deterioration of the fillets (about 1.5 log10 CFU/g) more efficiently than the SA.