Complete Guide to Medaka Shipping and Acclimation — Safe Receiving for Online and In-Person Purchases

When Welcoming New Medaka, the steps you must be most careful about are "transportation" and "water acclimation." Even medaka that are swimming vigorously at a breeder or shop can become stressed during transport due to vibrations, temperature fluctuations, and oxygen depletion, leading to illness after arrival. Especially when purchasing online, you cannot control the environment the medaka experience between packaging and opening, so how you handle them upon arrival can literally be the difference between life and death.

This article provides detailed explanations of both online and in-person purchase scenarios, covering the knowledge needed to minimize transportation risks and the correct water acclimation procedures.

Transportation Risks and Countermeasures for Online Purchases

Stress Medaka Experience During Shipping

When you purchase medaka online, they typically arrive packaged in a styrofoam box in plastic bags. The main stressors medaka experience during transport are:

• Temperature fluctuation: Depending on the season and shipping route, the temperature inside the box can vary significantly
• Oxygen depletion: The oxygen in the bag is finite, and the longer the transport time, the more oxygen depletes
• Water quality deterioration: Ammonia concentration rises due to medaka waste products
• Vibration: Shaking from trucks or air transport causes stress to medaka

Choosing Your Delivery Time Wisely

When ordering medaka online, paying attention to the following points ensures safety:

• Specify a delivery date and time: If you're not home and redelivery becomes necessary, the transport time increases and burden on the medaka grows. Choose a date and time when you can definitely receive the package
• Consider the season: During intense heat (over 35℃) or extreme cold (below freezing), temperature management during shipping becomes difficult and the risk of arrival dead increases. If possible, purchasing during mild spring or autumn weather is best
• Choose morning delivery: To minimize holdover time at distribution centers, morning delivery designation is ideal

Opening Procedure Upon Arrival

1. Check the room temperature before opening the box: Open the box in a place where air conditioning winds don't blow directly
2. Open the styrofoam lid and check the bag's condition: Look for water leaks or bag damage
3. Observe the medaka inside the bag: Check for individuals lying on their side or those with noticeably pale coloring
4. Take photos immediately after opening if there are arrivals dead: Most breeders and shops offer death-on-arrival guarantees, and photo evidence will be required
5. Don't remove from the bag immediately—move on to water acclimation preparation

Taking Home Fish From In-Person Purchases

When purchasing directly from a breeder, at an event, or at a shop, your risk is lower because you can manage the transport time yourself. However, be mindful of the following:

Important Points for Taking Fish Home

• Shorter travel time is better: Leave immediately and head straight home after purchase. Avoiding detours and leaving the bag in your car is absolutely forbidden
• Bring ice packs in summer: Prepare a styrofoam box and ice packs (wrapped in newspaper so they don't touch the water directly)
• Insulate with hand warmers in winter: Attaching disposable hand warmers to the outside of the styrofoam box prevents sudden temperature drops
• Keep the bag out of direct sunlight: Even in a car, avoid sunny spots and place the bag on the floor or in the shade of a seat
• Minimize shaking: Keep the bag flat and avoid sudden braking or sharp turns

Special Considerations for Event Purchases

When purchasing medaka at a competition or event, you often end up spending extended time at the venue. If you buy early, the medaka will continue to experience stress in the bag for the remainder of your time at the event.

• Ideally, purchase on your way out if possible
• If you purchase early, place the bag in a cooler to stabilize temperature
• When purchasing from multiple breeders, use dividers so bags don't rub together

Basic Water Acclimation Steps

Water acclimation is the process of gradually bringing the water quality and temperature of the transport bag closer to those of your tank, allowing the medaka to adjust to their new environment without sudden shock. Skipping this step risks pH shock or temperature shock, which can cause medaka to die within hours to days.

Step 1: Temperature Acclimation (30 minutes to 1 hour)

Float the unopened bag on the surface of your tank water. This gradually brings the water temperature inside the bag closer to your tank's temperature.

• Float for a minimum of 30 minutes, ideally 1 hour
• If outdoors, create shade with a reed screen to avoid direct sunlight
• For security, fix the bag to the rim of the tank with a clothespin so it doesn't flip over

Step 2: Water Quality Acclimation (Drip Method)

Once temperature acclimation is complete, open the bag and transfer the medaka and water to a plastic container or bucket. From here, gradually add water from your tank.

Drip method procedure: 1. Insert one end of air tubing into your tank and dangle the other end over the plastic container 2. Gently suck on the tubing to start a siphon and allow water to flow 3. Create a knot in the air tubing or attach a valve to control flow rate 4. Add water from your tank to the container at a rate of 2-3 drops per second 5. Continue until the water in the container doubles or triples in volume (approximately 30 minutes to 1 hour) 6. Remove half the water, then drip again to the original volume (repeat this 2-3 times for even greater safety)

Simple method (if you don't have drip equipment): - Add one cup of tank water to the container every 10-15 minutes - Repeat 4-5 times total, taking 40 minutes to 1 hour

Step 3: Moving the Medaka

Once acclimation is complete, transfer the medaka to your tank.

• Using a net to scoop is the standard method. The water in the plastic container may contain ammonia and pathogens from transport, so it's safer not to introduce it to your tank
• If you don't have a net, you can gently scoop by hand, but work quickly to avoid exposing the medaka to air for long periods
• Move quietly and don't drop them from a height

Care Tips Immediately After Introduction

First 24 Hours

After acclimating the medaka and moving them to your tank, observe them especially carefully during the first 24 hours.

• Don't feed: Transport stress reduces digestive function, so fasting for at least 24 hours (ideally 2-3 days) is safest
• Dim the lights (if indoors): Keep the environment dark to help them settle down
• Watch for gasping at the water surface: This indicates oxygen depletion. Add aeration or disturb the water surface to increase oxygen supply
• Individuals staying still at the bottom: Light stress responses typically resolve by the next day, but if any are lying on their side, consider salt bathing (0.5%)

First Week

• Start feeding small amounts from day 2-3: Initially feed less than half the normal amount and gradually increase while monitoring their appetite
• Limit water changes: To minimize environmental stress, avoid water changes during the first week (except if water quality noticeably deteriorates)
• Check daily for signs of illness: Watch for white spots, fin rot, body surface inflammation, and abnormal swimming behavior
• If introducing to existing medaka, allow a 1-week quarantine period: To prevent disease transmission, isolate new medaka in a separate container for at least a week before combining

Quarantine Method

Immediately introducing new medaka to your existing population risks spreading disease and is not recommended. Follow these quarantine steps:

1. Prepare an isolation container: A 5-10L plastic container or bucket is sufficient
2. Perform salt bathing at 0.5%: Mix 5g salt per 1L of water (use sea salt or coarse salt; avoid table salt which contains iodine)
3. For 3-7 days, change half the water daily: Make fresh salt water each day
4. If no abnormalities appear, move to your main tank: Perform a simple water acclimation even when combining

Seasonal Transportation Strategies

Spring and Autumn (Recommended Season)

Temperatures typically stay in the 15-25℃ range, making these ideal shipping seasons. Special heating or cooling is usually unnecessary, though if early mornings or evenings are cold, use a styrofoam box as a precaution.

Summer (Caution Required)

When water temperature exceeds 30℃, stress on medaka increases sharply. For online purchases, breeders often include ice packs, but shipping delays can reduce cooling effectiveness.

• Check the bag's water temperature immediately upon arrival
• If water temperature is notably high (over 30℃), don't briefly float the bag in ice water; instead, let the temperature drop naturally in an air-conditioned room
• Rapid cooling actually causes shock and is absolutely forbidden

Winter (Caution Required)

When water temperature drops below 10℃, metabolism slows dramatically, reducing recovery capacity from transport stress.

• Upon arrival, if bag water temperature is 10℃ or below, gradually return it to room temperature
• A sudden temperature increase risks shock death, so limit warming to 2-3℃ per hour
• If purchasing in winter, prepare a heater-controlled tank indoors for quarantine as a precaution

Welcome New Medaka Safely Through Brichoku

Brichoku allows you to purchase directly from medaka specialists, so you can consult in advance about packaging methods and shipping care. Breeders regularly ship medaka and are well-versed in optimal packaging for each season. If you're unsure about water acclimation methods or anxious about your first online purchase, you can message breeders before purchasing to get advice and prepare confidently for their arrival. To successfully welcome your valued medaka, find a trusted breeder through Brichoku.