DNA barcoding detects resurrected taxon Giuris laglaizei (Sauvage 1880) in Sulawesi, Indonesia: Bolano Sau Lake payangka phylogeny, phenotypic characters and implications for Giuris spp. conservation.

Background: The freshwater ichthyofauna of Wallacea is diverse and understudied. A baseline survey of Bolano Sau Lake in Parigi Moutong District, Central Sulawesi Province, Indonesia in 2019 found an eleotrid goby (local name payangka) with characters conforming to the genus Giuris, long considered monophyletic as G. margaritacea/G. margaritaceus but recently found to comprise at least eight species. This study focused on the molecular (DNA barcoding) identification and phenotypic characters of the payangka. Methods: Payangka samples were collected from August to December 2019 in collaboration with local fishermen, weighed and measured, and preserved in 75% ethanol. Length, weight, sex (n=111) and seventeen morphometric characters/six meristic counts (n=42) were recorded. DNA barcoding was performed on a fin clipping preserved in 96% ethanol. Homologous nucleotide sequences were obtained from public (GenBank and BOLD) databases, analysis conducted in MEGA X, and phylogenetic trees edited in the Interactive Tree of Life (iToL). Results: Within the polyphyletic Giuris clade, the payangka sequence resolved into a sub-clade identified as Giuris laglaizei (Sauvage 1880), a recently resurrected taxon, based on a sequence provided by Philippe Keith. The length-weight relationship (L = 0.0087∙W3.162) indicated mildly allometric positive growth. Size distribution differed significantly between male and female fish with significantly larger mean size of males (13.56 cm) than females (11.62 cm). The meristic formula was: D VI-I,8 A I,8 P 13 V I,5 C15. Phylogenic analysis indicated four Giuris species in wetlands around Tomini Bay and five in Sulawesi. Conclusions: This first record of G. laglaizei in Indonesia advances knowledge of Wallacean and Indo-Pacific gobioid biogeography and highlights the need for a revision of the conservation status of the taxa currently grouped under Giuris margaritacea/G. margaritaceus in the IUCN Red List and FishBase databases. The data will inform biodiversity and fisheries management at local and regional levels.

Perspectives on sustainable management of the Poso Lake (Indonesia) endemic ricefish, Oryzias nigrimas (Actinopterygii: Adrianichthyidae) / Perspectivas sobre el manejo sostenible del pez Oryzias nigrimas, endémico del Lago Poso en Indonesia (Actinopterygii: Adrianichthyidae)

Introduction: The endemic fishes of the ancient lakes of Sulawesi are under increasing threat. Objective: To evaluate the data and information available from a holistic management perspective and to formulate measures to conserve the endemic ricefish Oryzias nigrimas in Poso Lake, Indonesia. Methods: Collection of primary data from three stations around Lake Poso and literature study. Results: Threats to O. nigrimas include habitat degradation and loss, introduced alien species, and exploitation as a locally important food fish. Options to promote sustainable fisheries management include spatial and temporal limitations to minimise catch of gravid or brooding fish. Habitat protection should include measures to minimise impacts from activities which can reduce water quality and disturb or kill aquatic vegetation. Conclusion: Measures to prevent further O. nigrimas population decline are considered urgent and further research is recommended to fill identified knowledge gaps. Ex-situ conservation, including the development of captive breeding, could also contribute to a holistic O. nigrimas conservation strategy.

Introducción: Los peces endémicos de los antiguos lagos de Sulawesi están cada vez más amenazados. Objetivo: Evaluar los datos y la información disponible desde una perspectiva de gestión holística y formular medidas para conservar el pez endémico Oryzias nigrimas en el lago Poso, Indonesia. Métodos: Recopilación de datos primarios de tres estaciones alrededor del lago Poso y revisión de la literatura. Resultados: Las amenazas para O. nigrimas incluyen la degradación y pérdida del hábitat, la introducción de especies exóticas y la explotación como producto pesquero de importancia local. Las opciones para promover la ordenación pesquera sostenible incluyen limitaciones espaciales y temporales para minimizar la captura de peces grávidos o reproductores. La protección del hábitat debe incluir medidas para minimizar los impactos de las actividades que pueden reducir la calidad del agua y perturbar o matar la vegetación acuática. Conclusión: Las medidas para prevenir una disminución de la población de O. nigrimas se consideran urgentes y se recomienda realizar más investigaciones para llenar los vacíos de conocimiento identificados. La conservación ex situ, incluido el desarrollo de la cría en cautividad, también podría contribuir a una estrategia de conservación holística de O. nigrimas.