​Discrimination of Five Gobid Species (Family: Gobiidae) based on Otolith Morphometry

Background: The fishes of family Gobiidae are one of the least studied fishes, especially for otolith structure. The otoliths were possess species specific features. Hence, traits of sagittal otolith of gobid species studied. Methods: Five gobid species Odontamblyopus roseus (Valenciennes, 1837), Trypauchen vagina (Bloch and Schneider, 1801), Glossogobius giuris (Hamilton, 1822), Parachaeturichthys polynema (Bleeker, 1853) and Boleophthalmus dussumieri (Valenciennes, 1837) were investigated by three methods including morphological, shape indices and step wise discriminant function analysis (SDFA). Result: Interrelationship between shape indices investigated, at 95% level of confidence (P less than 0.05), revealed that perimeter of P. polynema and area of T. vagina have isometric growth with their length (b = 3.0071, 2.90, respectively) and otolith area of B. dussumieri have positive allometric growth (b = 4.23077). SDFA, based on otolith morphometry, discriminated species up with 97.18% accuracy. Hence, the results of present investigation can be used for discrimination of the species and as a tool in predicting fish size from the otoliths and in calculating the biomass of these less studied fish species.

Length–weight relations of 11 goby species (Actinopterygii: Gobiiformes) from mangroves along the Ba Lat estuary of the Red River, Vietnam

Presently reported study examined the length–weight relations for 11 goby species collected from a mangrove estuary of the Red River, Vietnam. A total of 1097 individuals of the following species, representing three goby families, were analyzed: Butis butis (Hamilton, 1822); Butis koilomatodon (Bleeker, 1849); Acentrogobius moloanus (Herre, 1927); Acentrogobius viridipunctatus (Valenciennes, 1837); Apocryptodon madurensis (Bleeker, 1849); Aulopareia unicolor (Valenciennes, 1837); Glossogobius giuris (Hamilton, 1822); Gobiopsis macrostoma Steindachner, 1861; Mugilogobius abei (Jordan et Snyder, 1901); Tridentiger barbatus (Günther, 1861); and Tridentiger trigonocephalus (Gill, 1859). The regression slope values (b) ranged from 2.909 to 3.621. The majority of species had positive allometric or isometric growth pattern with b ≥ 3, except for only one species (G. giuris) which had a negative allometric growth with b = 2.909. This study provided the first LWR information of four gobies that have not been reported in FishBase yet. Besides, the reference for LWRs of other gobies at an ecologically important area like Ba Lat Estuary is also provided.

Length–weight relations of 11 goby species (Actinopterygii: Gobiiformes) from mangroves along the Ba Lat estuary of the Red River, Vietnam

Presently reported study examined the length–weight relations for 11 goby species collected from a mangrove estuary of the Red River, Vietnam. A total of 1097 individuals of the following species, representing three goby families, were analyzed: Butis butis (Hamilton, 1822); Butis koilomatodon (Bleeker, 1849); Acentrogobius moloanus (Herre, 1927); Acentrogobius viridipunctatus (Valenciennes, 1837); Apocryptodon madurensis (Bleeker, 1849); Aulopareia unicolor (Valenciennes, 1837); Glossogobius giuris (Hamilton, 1822); Gobiopsis macrostoma Steindachner, 1861; Mugilogobius abei (Jordan et Snyder, 1901); Tridentiger barbatus (Günther, 1861); and Tridentiger trigonocephalus (Gill, 1859). The regression slope values (b) ranged from 2.909 to 3.621. The majority of species had positive allometric or isometric growth pattern with b ≥ 3, except for only one species (G. giuris) which had a negative allometric growth with b = 2.909. This study provided the first LWR information of four gobies that have not been reported in FishBase yet. Besides, the reference for LWRs of other gobies at an ecologically important area like Ba Lat Estuary is also provided.

SỰ BIẾN ĐỘNG CỦA MỘT SỐ CHỈ TIÊU HÌNH THÁI CỦA CÁ BỐNG CÁT TỐI Glossogobius giuris PHÂN BỐ Ở MỘT SỐ TỈNH ĐỒNG BẰNG SÔNG CỬU LONG

Nghiên cứu bổ sung thông tin về sự thay đổi thông số hình thái của Glossogobius giuris. Tổng số 1.291 cá thể cá được thu ở bốn địa điểm: Cái Răng (Cần Thơ), Long Phú (Sóc Trăng), Hoà Bình (Bạc Liêu) và Đầm Dơi (Cà Mau). Mẫu được thu bằng lưới đáy trong 12 tháng của năm 2020. Kết quả phân tích cho thấy khối lượng (W) thay đổi theo điểm, mùa và giới tính, trong khi chiều dài tổng (TL) chỉ thay đổi theo giới tính. Sự tương tác của mùa ´ địa điểm cũng ảnh hưởng đến sự thay đổi W và TL. Thông số khác như cao thân (BD), dài đầu (HL), khoảng cách mắt (ED), đường kính mắt (DE) cũng có thay đổi theo điểm, mùa và giới tính. Ngoài ra, các tỉ lệ HL/TL, BD/TL, ED/HL và DE/HL biến đổi theo giới tính, mùa, điểm, giới tính ´ địa điểm, mùa ´ địa điểm; nhưng không chịu sự chi phối của giới tính ´ mùa. Những kết quả này là cơ sở cho việc định danh và hiểu biết về sự thích nghi sinh thái của loài cá này ở Đồng bằng sông Cửu Long.

A review of the Glossogobius giuris complex in Australia, with wider discussion on nomenclature and possible synonymies

Two species that had previously been referred to as Glossogobius giuris from Australia are redescribed and tentatively treated as Glossogobius giuris and Glossogobius laticeps. The two species are largely allopatric in Australia with G. laticeps found on the east coast of Queensland and some rivers of the Northern Territory, while G. giuris is distributed from the Northern Territory to rivers of the west coast of Western Australia. The two species are known to be genetically distinct and with some differences in colour patterns. Morphological features separating the species are minor and there is considerable overlap in many of the characters separating them. High variation in the Hammersley Ranges and Kimberley region of Western Australia further complicates separation of the species. The status of the Glossogobius giuris group from India is discussed as a key area to resolving an overall “giuris” species complex. Information is provided on the current identity of a number of species that had previously been considered synonyms of Glossogobius giuris. Extant types and difficulties assigning the types of known species are also discussed. A key is provided to aid identification of Australian species of Glossogobius.