Breeding Dwarf Snakehead

Dwarf Snakeheads are some of the more colourful snakeheads around and usually grow to a maximum of 20 cm. In order for a pair to breed, the aquarium needs to be bio-tope correct according to the natural requirements of this species.

This species is best bred in a species only aquarium with a breeding pair. Seasons have to be mimicked, so during the winter months the temperature of the aquarium should drop to around 15°C and the fish should be fed only when they beg to be fed (maintain this for at least 10 weeks). Then, gradually raise the temperature with regular 50% water changes to mimic the arrival of the rainy season. Dwarf Snakeheads are not too fussy of the water parameters as long as extremes are avoided. Tap-water should be fine.

In the wild Dwarf Snakeheads breed at the end of their winter period, before the majority of the rain comes. Dwarf Snakeheads will breed when the water temperature is around 24-26°C. After the eggs are released the male will incubate the eggs in its mouth while the female guards the territory. Incubation period is between 5 to 8 days. Once “hatched”, the fry will be fed by the female that squirts out infertile eggs as food for the fry. It is therefore important to feed the female. After about two weeks, the fry can be given flakes.

Tank set-up:

  • At least 90cm/36in tank
  • Fine sand
  • A fair amount of plants
  • Plenty of hiding places like plastic pipes and hollow logs
  • Floating plants…MUST! This will give shadow and increase activity of the snakeheads
  • Filtration is not necessary as long as you have a substantial amount of plants
IMG20170512223026Dwarf Snakehead species, Channa Bleheri (picture from MP&C Piednor.Aquapress.com)

 

 

Engineering with Membranes 2017

Between the 26th and 28th of April the annual Engineering with Membranes was held in Singapore organised by the Singapore Membrane Technology Centre (SMTC). The main goal of the conference was to share knowledge on recent advances in membrane science and technology. Leading membrane specialists from around the world gave a total of 70 lectures covering desalination, reclamation & resource recovery, molecular separation, membrane fouling, gas separation, pre-treatment, industrial & bioprocess application and membrane monitoring. The Dutch representative at this conference was Dr. Emile Cornelissen, senior researcher at KWR, who presented his research on controlling Reverse Osmosis (RO) fouling after minimal pre-treatment. His main conclusion was that the 1-step RO scenario was approximately 20% lower in costs than the Ultrafiltration (UF) – RO scenario. Air/water cleaning is effective to control clogging, while lowering flux values results in less membrane fouling.

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Giant Snakehead

The Giant Snakehead, channa micropeltes, is one of the largest snakehead species. Lengths over 1 meter are regularly encountered. They are found throughout South-East Asia and have been introduced elsewhere in the world where they are considered an invasive species. Giants Snakeheads are highly adaptable and have the ability to crawl onto land and breath air in muddy conditions. They possess a primitive lung, located behind the gills, which it uses to gulp air. It can therefore travel short distances over land!

These fish are ferocious predators and will chase down anything that will fit in their mouth. They have very sharp teeth that can rip fish into half. It should therefore only be kept in aquaria with similar sized fish, but even then it is risky. Despite its aggressive nature, it is a very beautiful fish with juveniles having distinctive bright lines across their body.  As the fish grows older they develop a pattern comprising a broad, dark longitudinal stripe. Adults will defend their brood at all costs and have occasionally injured humans.

IMG_65174Pictures above is thanks to Zooish from Zoochat

NEWater Singapore

One of Singapore’s four national “water taps” is to reclaim water from wastewater. After years of research, the Public Utilities Board (PUB), Singapore’s national water agency, started to supply high quality reclaimed water, referred to as NEWater. The majority of NEWater is supplied to industries for non-potable purposes. The rest is discharged into reservoirs for indirect potable use. Currently NEWater meets 30% of Singapore’s current water demand, and there are plans to increase this to 50% by 2060. At this moment there are four NEWater treatment plant in service (Bedok, Kranji, Ulu Pandan and Changi). NEWater is produced from treated sewage, termed “used water”, that is further purified in three different steps:

  1. Microfiltration (MF) is the first step in the NEWater production. The treated used water is passed through membranes to filter out and retained on the membrane surface suspended solids, colloidal particles, disease-causing bacteria, some viruses and protozoan cysts.
  2. The second stage of the NEWater production process is known as Reverse Osmosis (RO). In RO, a semi- permeable membrane is used. The semi-permeable membrane has very small pores which only allow very small molecules like water molecules to pass through. Consequently, undesirable contaminants such as bacteria, viruses, heavy metals, nitrate, chloride, sulphate, disinfection by-products, aromatic hydrocarbons, pesticides etc, cannot pass through the membrane.
  3. The third stage of the NEWater production process acts as a further safety back-up to the RO. In this stage, ultraviolet or UV disinfection is used to ensure that all organisms are inactivated and the purity of the product water guaranteed (PUB).

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(Reverse osmosis membranes)

Tiger Barb

The Tiger Barb is a beautiful fish that is found in clear or turbid shallow waters of moderately flowing streams. They live in Indonesia and Borneo and their average lifespan is about 6 years. It has four very distinctive black stripes, which resembles the pattern of a tiger. These fish are very active and playful, which makes them fun to watch. They are also fairly hardy and easy to keep provided that frequent water changes regularly occur. The species does need company, and will do best with 6 or more in a group. Having schools of 20+ will make these Tiger Barbs look even more spectacular! DO NOT house these fish with long-finned or slow-moving fish as Tiger Barbs are well known fin-nippers! Gouramis and Anglefish should not be housed together with Tiger Barbs. When Tiger Barbs are kept in larger groups they tend to be less aggressive as they are more busy chasing each other. I personally like to house Tiger Barbs with other fish of Sumatran biotope, such as Bala Shark and Clown Loach.

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Roti Island Snake-necked Turtle

The roti island snake-necked turtle is an oddly shaped freshwater turtle found only on the Indonesian island of Rote. The neck is nearly as long as the carapace of the turtle and is extremely mobile. In the wild it only exists in small isolated pockets in the central highlands of Rote Island. The species is an island endemic and is very susceptible to human interference. The exotic pet trade has decimated this species in the wild as it is one of the most desired turtle in the international pet trade.

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Giant Pangasius

The Giant Pangasius, or Paroon Shark, is a huge fish inhabiting the Mekong River Basin in South East Asia. It can reach an incredible length of 3 metres! It is not a shark, but rather a species of whisker-less catfish. It is a migratory fish and lays its eggs just before the monsoon season. It has a perfectly streamlined body with an elegant dorsal fin. The natural population has declined drastically over the last couple of decades as a result of overfishing. This has made the remaining Giant Pangasius populations severely fragmented and critically endangered.

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Blood Parrot

The blood parrot is an interesting fish with a round balloon-shaped body and a small mouth. Since it’s a hybrid developed by humans it does not occur in the wild. They come in many colours, but the most striking ones are those with yellow or red colour. The blood parrot is very popular aquarium fish. It is a hardy fish and is therefore easy for the beginner  They are, however, messy eaters and will only consume part of the food that is given. A powerful filter and good cleaning of the substrate is necessary when keeping these fish. Originating from cichlid parents, one would expect these fish to be aggressive. However, this is far from the case and these fish can easily be housed with similar sized fish such as Angelfish, Corydoras, Silver Dollars and many catfish species.They are called parrotfish because their nose looks like the beak of a parrot 🙂

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Wels Catfish

The Wels catfish, Silurus glanis, is one of the largest fresh water fish in the world. Accurate measurements over the last couple of decades have shown several specimens of over two metres in length, the longest and heaviest being 2.78m (144kg). It’s a not the most attractive fish you will ever see as it has a long snake-like body, with slimy skin and a huge mouth. Using its long barbels, it tracks its prey by hearing and smelling. The eyesight of a Wels catfish is fairly poor, but it enjoys a tapetum lucidum which gives it reasonable vision at night. They eat insects, crustaceans and other fish. The larger ones go after small mammals and aquatic birds. It is rarely kept in the aquarium due to its sheer size.

This giant fish has been introduced in several European rivers, including the Seine and Po rivers in France and Italy respectively. In some areas, they are known to lunge out of the water to grab pigeons on land. Check youtube for video’s on this! Also the 6th season “cities” of the BBC’s Planet Earth II series spends time covering this phenomena.

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Photo from the Watershed Council Petoskey

Colloquium Master Thesis

On Thursday the 16th of February 2017, I held my colloquium at Wageningen University of my master thesis covering the sanitation issue in Ciwalengke, Majalaya, Indonesia.

This master thesis research examined the important issues that play a role for successful implementation of domestic sanitation treatment facilities and the potential for nutrient harvesting in Ciwalengke. Based on field observation, water sample analysis, questionnaires and interviews a new sanitation design was proposed specifically for the case of Ciwalengke. It incorporated both a technical and institutional design. The technical design concluded that storage of urine and the treatment of the remaining wastewater through septic tanks were the most feasible technologies. The institutional design concluded that a solid platform would be necessary that incorporates community involvement in the maintenance and operation of the sanitation system. Governmental guidance coupled with a financial structure should be in place to facilitate this process.

It was great to see many students of my year and others attending this 🙂 Thank you all for coming!

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