Shallow stream in the dry season, S. Wosea, DS. Sawai, Weda Tengah, Halmahera, Maluku, Indonesia

_ place in Biotope Aquarium Design Contest 2019

Volume: 68 L
Dimensions: 60x45x25 cm
List of fishes: Stiphodon annieae, Stiphodon rutilaureus, Stiphodon semoni
List of plants: In the habitat I described, there were no aquatic plants except those that were flooded during the rainy season.
Description of decorations: All the elements used in my aquarium, such as driftwoods, leaves, stones, rocks, substrates were collected from a wild stream. The substrate of the aquarium is sand with dark color. I piled up a slope with sand and placed some stones on top of substrate to simulate the gradient of the real riverbed. The lowest depth of the water is only 3 cm, and the highest point is nearly 20 cm. Some broken branches and fallen leaves are randomly arranged in the cylinder which slowly and naturally decomposed with the establishment of the ecological environment. These corrupted fallen leaves not only provide shelter space for the Stiphodon annieae but also provide additional food sources. The landscape is just a small reflection of the real nature environment of the slow flowing stream which I want to demonstrate. Prosperity, decline, ablation, and regeneration are just a microcosm of the natural ecological cycle.
Description of equipment: EHEIM 600 classic filter (1000L/H), Netlea 50w LED, 7500k color temperature
Water parameters: The water is clear. Temperature is from 23 to 27°C, PH is 7, GH is 7
Additional info: 2 times of water change in a week

INFORMATION ABOUT BIOTOPE

Description of the area surrounding the biotope: Halmahera, also known as Jailolo or Gilolo, is the largest island in the Maluku Islands. It is located east of Sulawesi in western New Guinea. It is part of the North Maluku province of Indonesia. Sofifi, the capital of the province, is located on the west coast of the island. This island is consisting of 5 regencies: Halmahera Timur / east Halmahera, Halmahera Selatan / south halmahera, Halmahera Barat / west halmahera, Halmahera Utara / north Halmahera, and Halmahera Tengah / central Halmahera.

Most of the Halmahera Island is in the mountains. Small and narrow island is covered by luxuriant tropical rain forests. Due to the influence of the Kuroshio Current flows through the northern equator, the island has a humid climate throughout the year. The island is shaped in K letter, it almost like a miniature of Sulawesi island. By having white sandy beaches, pristine forests and spectacular Mamuya Mountain in the distance, the island offers stunning scenery.

Weda, the place I described, is situated in Halmahera Tengah and its geographical coordinates are 0° 21′ 0″ North, 127° 52′ 0″ East. There are many cherished species of birds in Weda, such as White Cockatoos, Eclectus Parrots, Redcheek Parrots, Dusky Scrubfowl, Hornbills, Paradise Crows, Goliath Coucals, Sombre Kingfishers, Halmahera Cuckoo Shrikes, Moluccan Cuckoo Shrikes. Every morning the jungle fills up with the singing of the legendary Standardwing Bird of Paradise (Semioptera Wallacei), the Ivory Breasted Pitta and the Common Paradise Kingfisher. Later at the day, the Wallace’s Golden Birdwing Butterfly (Ornithoptera croesus) and many other butterflies and can bee seen here. At least 28 endemic species of birds and countless species of insects have their habitat here.

Description of the underwater landscape of the biotope: The coastal stream, with clear and oxygenated water, goes through the forest. The lower course of river is characterized by rocky substrates, with boulders and pebbles. In the dry season, the river is very shallow, up to 40cm in the depth. there are no aquatic plants except for the plants that are submerged during the rainy season. During the rainy season, the water level rises and is poured into the surrounding forest. Many branches, driftwood and fallen leaves drop into the water. These provide abundant food and shelter for fish. Under the long-term sunshine, the stones are covered with brown algae and other algae. Stiphodon annieae, Stiphodon rutilaureus and Stiphodon semoni live on the bottom of the river, on top of rocks but it is also often seen swimming in open water in the current between rocks. They feed on algae and small invertebrates scraping them on the surface of rocks.

Description of the parameters of the habitat: The rainy season begins from July to ends in October. During the rainy season, the water level of the stream rises and the water temperature drop. The dry season starts from November to June. During the dry season, the water level in the stream decreased and the water temperature rise. The water temperature of the stream is between 24 and 30 degrees Celsius. The pH of the water is about 7 and the GH hardness is about 7.

List of fishes and invertebrates occurring in the nature biotope: Stiphodon annieae (Keith&Hadiaty, 2015, This species is only found in Halmahera of Indonesia), Stiphodon rutilaureus (Watson, 1996, This species occurs in Indonesia including Halmahera, Bali and Papua, Papua New Guinea, Solomon, Fiji, Vanuatu et. ), Stiphodon semoni (Weber, 1895, This species is widely distributed in Indonesia including Halmahera, Sumatra, Java, Bali, Sulawesi and Papua, Papua New Guinea and Australia)

List of plants found in the nature biotope: In this shallow stream, there are no aquatic plants except for the plants that are submerged during the rainy season.

Threats to the ecology: Sicydiine communities exhibit behaviours that are fostered by a number of environmental factors such as free passage, natural vegetation cover, unmodified flows, quality of estuaries, or the absence of introduced species. Reduced or disrupted surface flow of streams and rivers represents on of the greatest threats to population viability. Loss of connectivity disrupts contributions to the marine larval pool and post-larval recruitment to freshwater, while also reducing stream habitat required for reproduction. Climate chage may indirectly influence migratory behaviour.

With the continuous deforestation of forests and mineral resources, many tropical islands in Indonesia, including the Halmahera Island, are at risk of large-scale destruction of ecosystems, including endemic organisms including the Stiphodon annieae. Some green organizations and environmentalists are actively working to protect the environment in which countless lives depend on and to realize the harmonious coexistence of human survival and development and natural ecology. May these beautiful elves in the tank not become the last “living fossils” of this species left in the world.

Sources of information: 1. Stiphodon annieae, a new species of freshwater goby from Indonesia (Gobiidae)
https://www.researchgate.net/publication/279316272_Stiphodon_annieae_a_new_species_of_freshwater_goby_from_Indonesia_Gobiidae
2. Indo-Pacific Sicydiine Gobies Biodiversity, life traits and conservation, Philippe Keith, Clara Lord, Ken Maeda
3. Exploring the Stiphodon annieae in Weda, Halmahera, Maluku, Indonesia, Xiaofei Li
https://mp.weixin.qq.com/s/_-NEqAXPGa4xvXrRQb6T8Q

Comments of the members of the jury of Biotope Aquarium Design Contest 2019