Local people name Selaroides leptolepis distributed in Tomini Bay as Oci Fish. A study of the fish reproductive biology, which is one aspect of fisheries biology, is crucial to support the implementation of sustainable Oci Fish resource management policies. This study aims to determine the average length at first maturity, gonad maturity stages, and fecundity of the fish in Tomini Bay. Sampling was carried out using a stratified random sampling method from the catches of the fishermen landed in Fish Landing Base Kampung Tenda, Gorontalo City. The time interval sampling was conducted per month during April, May, and June 2020. Fish and egg samples preserved using ice cubes and a 10% formaldehyde solution correspondingly. The results of the study showed that the Oci Fish in Tomini Bay had a length range of the first maturity between 166 and 174 mm with a gonad maturity index ranging from 1.773 to 2.760%. The average fish fecundity was 16623 ± 4850 eggs.

Nike is a terminology used by Gorontalo local community to name schooling of minuscule amphidromous goby fish that has a limited appearance in Gorontalo waters. Understanding the biological performance of Nike fish is vital for implementing management and conservation strategy. This study aims to analyze daily recruitment and to determine growth patterns of Nike fish population in nature. Sampling was conducted in the Gorontalo waters during March, April, and May 2018 using a fish net with a mesh size of 0.5 inches. The duration of the appearance of Nike schooling in waters varies every month. The number of fish samples collected each month in this study ranged from 150 to 300 individuals. This study reveals that body color diversity and morphology of Nike fish strongly alleged to depend on where and how long they appear in the waters. Based on the daily recruitment pattern, Nike fish population distributed in Gorontalo waters is predicted to consist of individuals from multi-generation with an average length range of 1.848–2.805 cm. During the sampling time, a positive allometric growth pattern indicated by the population.

Data of the species scientific name is required to study biodiversity and conservation of local fish species. Nike and hundala are the local names for fish found in Gorontalo whose scientific names are unknown and recognized by local people as two different species of fish. This study aims to identify the genetic and species of nike and hundala fish. Nike and hundala specimens were collected using a fish net from the estuary of Gorontalo Bay and Bone River, Gorontalo, Indonesia in April 2018. Molecular analysis of fish over sequencing methods shows that nike and hundala at Gorontalo waters are alleged as Sicyopterus longifilis.

Gorontalo Bay, the estuary of the Bone River, is part of the Tomini Bay area. Nike, a school fish larva appearing in Estuary Bone only a few days monthly, suits the prima donna of the community and fishermen in Gorontalo. Any technical matters related to “nike” fishing have never been reported in a structured method. Therefore, scientific investigation is necessary to provide relevant information. This study aimed to identify the fishermen’s profiles and matters linked to “nike” fishing. Structured interviews using a questionnaire instrument were conducted to obtain information from Gorontalo fishermen who actively catch “nike” every month in Gorontalo Bay. The results showed that most “nike” Gorontalo fishermen are elementary and junior high school graduates aged 20-60. Nike fishing is done in groups using wooden boats with totalu'o or tagahu fishing gear. The operational fishing capital they used could be from boat owners, groups, or loans from fish collectors. Most fishermen sell their catch at the Fish Auction, Gorontalo City, with an average price of Rp. 20.000 to Rp. 40.000 per kg. According to fishermen, the “nike” fish population tends to be abundant in the waters during the east monsoon. When the population in the seas is high enough, the fishermen’s catch reaches more than 100 kg per trip. The high intensity of catching and the quantity of fish caught per season of emergence can threaten the sustainability of the “nike” population in nature. A more comprehensive follow-up study is needed to analyze the synergies of economic, social, and ecological aspects to increase “nike” fishermen’s welfare in Gorontalo with the sustainability of the “nike” fish guarantee.

Pasisingi N, Suci D, Panigoro C, Kadim MK. 2024. Morphological characteristic and truss morphometric analysis of amphidromous goby (‘nike') (Teleostei: Gobiiformes) in Bone River, Gorontalo, Indonesia. Biodiversitas 25: 223-231. One of the preferred fish resources in the Gorontalo region is amphidromous goby species, commonly known by local community as nike fish. In rivers, at the adult stage, these fish are morphologically and potentially morphometrically not necessarily distinguishable among species and between sexes. This research aimed to identify the morphological and morphometric truss characters that distinguish the sexual characteristics of goby fishes in the Bone River, Gorontalo. Fish samples were purposefully collected from eight sites along the river, spanning from upstream to downstream, using a backpack electrofishing device. Sampling occurred in March and November 2022, with morphological analysis and measurements conducted on 336 individuals. The morphometric method measured data from 13 points on the sample body, forming 28 combinations of truss distance characters (A1-A3; B1-B12; C1-C10; D1-D3) connecting these points. Morphologically, the samples were identified as three species, namely Sicyopterus longifilis, Belobranchus belobranchus, and Awaous grammepomus. This study revealed distinctions in morphological characters between male and female individuals. In S. longifilis, males exhibited a relatively slimmer body shape compared to the rounded form of females. Male B. belobranchus displayed more striking coloration than females, while male A. grammepomus featured a lighter brown body color than the paler females. All the morphometric truss characters in this study can be reliably used as a sexual distinguishing characteristic in S. longifilis. As for species B. belobranchus, B7 truss cannot be considered a differentiator. In A. grammepomus, thirteen truss characters (B3, B4, B6, B7, B8, B10, B12, C3, C6, C7, C9, C10, D1) cannot be used to differentiate males and females.