Microhabitat preferences of endemic Banggai cardinalfish (Pterapogon kauderni) in the introduced habitat in Luwuk, indonesia.
Banggai cardinalfish (Pterapogon kauderni) is known as an endemic fish species in Banggai Islands, Central Sulawesi. Recently, Banggai cardinalfish has been found in several regions of Indonesia, including in the coastal area of Luwuk, Central Sulawesi. The discovery of the Banggai cardinalfish population in Luwuk is a side effect of ornamental fish trading activities. Observation of the population of Banggai cardinalfish in habitats in Luwuk was carried out from late April to early May 2019 to obtain up to date data on population status and the microhabitat preferences of each life stage. The data were collected by scuba diving using a modified Belt Transect method, with 3 replicate transects (20 x 5 m) at each location. Observations of Banggai cardinalfish abundance, habitats (coral reefs, seagrass beds, other) and microhabitats (Diadema spp., sea urchins, corals, sea anemones) were carried out in each belt transect. Banggai cardinalfish were classified into 3 sizes based on standard length (SL): post-larval stage (less than 1.8 cm), juvenile (1.8 - 3.5 cm), and adult (more than 3.5 cm). The observations showed that Banggai cardinalfish populations were found in all five locations at varying densities. The total number of fish observed during the survey was 2673 individuals, consisting of 11.34% recruits (303 individuals), 22.67% juveniles (606 individuals) and 65.99% adults (1764 individuals). The lowest density was 0.11 ind m-2 at Kilo 5, and the highest density was 4.167 ind m-2 in the Port of Luwuk. At the other three locations (traditional harbor, Maahas and Simpong), the density was around 0.5 to 1 ind m-2. The majority (98.77%) of the Banggai cardinalfish were associated with sea urchins (Diadema spp.), while only 1.23% were found living in branching corals (Acropora spp.). The results show that the Banggai cardinalfish has been able to adapt and establish resident populations in several coastal areas of Luwuk that provide suitable habitat.