That Fish Blog – Aquarium Advice and Information

Please welcome Cory Shank to That Fish Blog. Cory is an on-staff marine biologist here and our resident “Coral Guy.” Take a look below to read his thoughts on the future of wild coral.

Corals reefs are enjoyed by millions of people each year, while on vacation or in the comforts of their own homes. Coral reefs are the most biodiverse ecosystems in the ocean and arguably in the world. It is well known that coral reefs are beginning to decline world-wide, from Australia to the Florida coastline. This is a major concern for industries economically involved, the aquarium trade, global tourism, and commercial food fisherman. The problem is, how do we stop this disturbing decline when we don’t know enough about the issues causing it?

 

The hype over global warming has many believing that the water temperature increases are causing the coral degradation. Water temperature plays a major role in maintaining the health of a coral reef ecosystem. In our aquariums, we use fans and chillers to keep our tanks at a desirable temperature, but reefs depend on natural currents and climatic conditions. In the past, the world climate has warmed much faster and more dramatically and the corals have lived on. The El Nino event of 1997-98 caused massive coral bleaching throughout the world’s coral reefs. Ten years later, many of these areas have recovered and are showing signs of expansion. So it is reasonable to believe that this cannot be the only reason behind the coral destruction.

 

So, what else can be going on? I was in Hawaii recently and spent most of my time in the water observing the wonderful fish, corals, and invertebrates. I noticed quite a bit of new coral growth and plenty of fish. However, there were areas that were not doing so well. Along the main highway, just off shore, were large coral colonies covered in filamentous algae and diatoms, not at all what the reefs looked like 5-10 miles offshore.  There the corals were thriving, and no algae could be seen. Along the shoreline, there are drainage pipes coming from the roadways and further up the mountains. This is where all of the runoff ends up. With more development come more impervious surfaces, chemicals, soil, and debris that enter the oceans, increasing the amount of siltation that occurs from the breakdown of coastal buffer zones. The soil and debris enter the ocean, choking out the coral. This also adds nutrients to the water, leading to enhanced algae growth, which also chokes out the coral. Coastal development is occurring all over the tropics, and new resorts and hotels and homes are being built every year, increasing to the problem.

 

With the increasing amount of hotels and resorts near where the coral reefs are located,  tourism poses a new wave of problematic issues. There are snorkelers and divers who may not respect the reefs and act irresponsibly, stepping on the corals, catching the fish, and polluting the waters. While in Hawaii and the Florida Keys on separate trips, I have witnessed people standing on corals with their snorkel fins not considering the damage they may be causing. The amount of trash floating around, stuck in between corals, or just buried in the sand is appalling and virtually unavoidable these days.

 

If Global Warming is occurring, causing the sea surface temperatures to rise, then everyone needs to step up and start protecting the reefs in any way that we can. At the current rate of degradation, a large percentage of coral reefs may disappear in the next 10 to 20 years. This will have devastating economic impact on the locals populations and to everyone else in the world that relies on income from those areas around the world.   Skyrocketing prices on everything from ornamental aquarium specimens to the shrimp for your picnic or barbecue will be the likely result, as these things become harder to come by. It is going to take a worldwide effort to help save the coral reefs, and we are running out of time, so please do your part and help protect our most biodiverse ecosystem.

 

Thanks for the great article Cory. Please write in with your thoughts or observations on this important topic.

Until next blog,

Dave

 

One of the most frequently asked questions that customers who are considering their first aquarium ask is how hard is it to clean and maintain an aquarium, particularly if they’re thinking about a saltwater aquarium, because they may have heard that it is very difficult to maintain. If you have a few basic tools, and follow some simple guidelines, then keeping your aquarium clean is easy, and does not require a great deal of time.

If any piece of equipment is a “must” have, then a gravel siphon is it. A gravel siphon will remove water from your aquarium and clean your gravel at the same time. A gravel siphon is a simple device that uses a small diameter flexible tubing that is attached to a larger diameter plastic tube that goes into your aquarium. The large diameter plastic tube is plunged into your gravel, and removes water at a slow speed that will tumble and clean the gravel without sucking it out of the tank. When the water reaches the small diameter tubing it accelerates and removes only the dirt from the gravel and water. There are two styles of gravel siphon, a simple version like the Lee’s aquarium products Gravel Cleaner, that uses gravity to remove water through a shorter length of tubing into a bucket, or other container. There are also more advance cleaning systems, like the Aqueon Water Changer and the Lee’s Ultimate Aquarium Gravel Vac, that attaches to a sink faucet and uses the water pressure of your tap to draw water through a length of tubing up to 100’ with a venturi attachment that fits any standard faucet. The advantage to the more advanced system is that the flow can be reversed at the faucet end to actually fill your aquarium back up after all the dirt has been removed from the gravel. What could be easier than that! If you have a chlorinated water source you will need to add a water conditioner at the same time. Gravel siphons are available for just about any size aquarium.

One of the best inventions to come along in aquarium cleaning products is the magnetic algae cleaner for your aquariums glass or acrylic panels. With the use of two magnets, one inside the aquarium and one outside, you can clean all of you viewing panels without the need to put your hands in the aquarium. The inside magnet has a cleaning surface that removes algae from the inside glass, you simply stick the two magnets together with the aquarium glass in between, then move the outside magnet around until all the algae is gone. This is a simple device, that has dramatically improved the ease and speed that you can clean your glass. In recent years manufacturers have invented a magnet cleaning system that has a floating inside magnet, so you never lose the cleaner to the bottom of the aquarium, which was the downfall to initial models if you moved the outside piece too quickly. Floating magnets like the Magfloat and the Magnavore, are available for most sizes of aquariums in both glass and acrylic safe models.

Just as important as the gravel siphon and the magnet cleaner is following some basic husbandry guidelines to help keep your aquarium clean.  Replace your filter cartridges, or filter media, at least once a month, make sure that you are not overstocking and overfeeding your aquarium, and make sure that you keep to a schedule. Small water changes on a weekly or biweekly basis will ensure that your water quality stays at a high level, which will inhibit excess waste build up and algae growth. All of these things are easy to do, and take very little time. If you procrastinate in maintaining the tank, or wait until there is a problem, then correcting issues becomes more difficult and time consuming.

Aquarium keeping should be fun and easy, follow these tips and guidelines, an you should be headed for success.

Until Next Blog,

Dave

Note:  Please see Part I of this article, New Facts on Vision, Florescence and Movement, for natural history and other general information.

 

General

Mantis shrimp engender strong feelings among marine aquarists – to many, they are highly valued pets – responsive, complex and long-lived.  However, small specimens sometimes arrive unnoticed among live rock and make themselves unwelcome by devouring expensive fish and other creatures.  Either way, these alert predators are among the most interesting marine invertebrates available in the pet trade.

 

Mantis shrimp mannerisms, in my opinion, inspire one to wonder about their intelligence – they definitely seem to peer at their owners, and are very aware of all that goes on around them (see Part I of this article).  The various species exhibit a startling array of neon-like colors, and even the drabber temperate types are often interestingly patterned in tans and browns.

 

Aquarium Size and Physical Set Up

Although water quality is more easily managed in large aquariums, small mantis shrimp do quite well in 10 gallon aquariums.  Individuals longer than 8 inches or so do best in a tank of 20 gallons or larger.

 

A secure retreat, preferably a burrow below the substrate, is essential.  Despite their fearless attitude, mantis shrimp will languish and die if forced to remain in the open.  Providing a proper home will result in your seeing your pet more, not less, as it will feel secure enough to behave normally.  Artificial rocks work well. Mantis shrimp will also explore rock and coral mounds, move incredibly large amounts of sand and gravel from one place to another, and sometimes manage to create quite stable burrows of their own.

 

Temperature and Water Quality

Most species thrive at temperatures of 74-80 F, and at salinities of 1.020-1.022.  However, various species range from temperate to tropical waters, so please research the natural habitats of those you keep.  Setting a light timer to mimic their natural cycle (i.e. varying the cycle for temperate species) will likely benefit their over-all health.

 

Filtration can be quite simple for small aquariums, (i.e. an under-gravel filter).  Larger aquariums will require a suitably powerful canister or other filter.  Mantis shrimp are reasonably hardy as concerns water quality but are, like many aquatic invertebrates, quite sensitive to air-borne chemicals.  Fumes from cleaning products, paints, floor waxes and such may be introduced into even covered aquariums by the filtration system, and can be toxic to mantis shrimp.  Unexplained aquarium deaths can often be attributed to chemical poisoning.

 

Feeding

Depending upon the species, mantis shrimp catch their food using either of two distinct methods.  Those which “club” their food and shatter the shell or carapace (see Part I) can take small crabs, crayfish, snails, mussels and other invertebrates.  Those that grab or spear their prey are best fed shrimp, fish and aquatic worms (the “prey bashers” will accept these as well).

 

Mantis shrimp can be quite choosy when it comes to feeding – sometimes killing a live food item, seemingly as a territorial defense, but not consuming it.  Most will, however, adjust to unfamiliar foods over time.  They will, if you work carefully, usually accept dead food from a forceps (do not use your fingers, as serious injury can result).  This takes time and experimentation – actually, it is quite comical to see them grab an unfamiliar food, retreat into their den, and then contemptuously toss it out as unpalatable!

 

Tong-feeding will allow you to provide them with a more varied diet than if you relied solely upon live food.  Frozen mussels, clams, prawn, scallops, crab, squid and various fishes are all readily accepted.  Seafood (human) markets and bait stores are also excellent sources of unique food items (different shrimp, fish, snail and abalone species, for example) – including such in your pet’s diet will go a long way in promoting good health.

 

Captive Longevity

Mantis shrimp have lived for over 20 years in captivity.

 

Handling

Mantis shrimp strike out viciously with their second pair of appendages (maxillipeds) when threatened, and can cause severe injuries requiring stitches (shrimpers and divers call them “thumb splitters”).  The speed of this movement has been calculated at over 20 miles per second, and likened to the force of a small caliber bullet.  Indeed, mantis shrimp have broken aquarium glass (this is not at all common, but watch them at feeding time).

 

They also have a strong feeding and burrow defense response, and so may attack fingers moved in their vicinity.  Always use a tongs or other similar tool when working in the tank, and use a net if handling is necessary.

 

Social Groups and Breeding

It is almost impossible to house more than 1 mantis shrimp in an aquarium, unless it is very large and complex in its set up.  That being said, their breeding behavior is fascinating (please see Part I) – pairs may remain together for 20 years and care for their eggs and each other.  It would be well worthwhile to attempt to house a pair together, just be sure to have a spare tank set up in advance. 

 

Males may be distinguished by the presence of organs known as penes.  Used to transfer sperm, these slender structures are at the base of the last pair of walking limbs.  Males of many species are also larger than females.

 

Mantis shrimp larvae are planktonic in nature, and thus not likely to survive in the aquarium, but a mated pair would be most interesting to study none the less.

 

Thanks for your interest – we have a lot to learn about these creatures, so please pass along your observations and questions.  Until next time, Frank.  

 

Additional Resources

Photos of a variety of mantis shrimp species are posted at:

http://images.google.com/images?hl=en&q=mantis+shrimp+photos&um=1&ie=UTF-8

Please welcome back Patty Little to That Fish Blog. Patty has previously written such articles as Water Gardening in Natural Ponds & Preparing Your Pond Plants After Winter. Please welcome Patty Back to That Fish Blog.

As aquarists, we may find ourselves in a constant quest to find the next unique and interesting creature to enhance our underwater display.   We may not always consider shrimp when we ponder species to add, but if you’re looking for something new, particularly if you have a planted community, freshwater shrimp species may be just what you’re looking for.  Shrimp are not only fun to observe, but in many cases they serve as efficient cleaners.

There are several species of freshwater shrimp offered commonly in the aquarium hobby, some more often than others.  Let me introduce you to the first two species you may encounter in your quest.  I’ll talk about some others in my future blogs.

Ghost Shrimp

Ghost shrimp, aka glass shrimp, are probably the most common shrimp offered in the trade, but they are usually offered as a live food source or treat for predators, both marine and freshwater.   These guys are terrific additions to the home aquarium, as they serve as scavengers as well as consumers of soft algae on rock, wood, and other surfaces.  These shrimp, Palaeomonetes sp., are hardy, inexpensive, and low maintenance.  They are virtually translucent, though some may be slightly more opaque with a hint of white or green to their exoskeleton, and a small orange or yellow dot adorns the tail.  The contents of their stomach, or at least the color of their last meal is quite visible.  They have ten pairs of legs, the front 2 tipped with small claws for feeding. Ghost shrimp grow to about 2 inches, and they tend to grow quickly.
They do not tend to have long lives, maybe about a year or so.  Be sure to ask your source if they are housed in freshwater, as there are some species that are brackish or marine, and will not tolerate full freshwater for extended periods. Otherwise, they are fairly undemanding.  They prefer a clean environment with low to neutral Ph, and temperatures ranging from the low 60’s to the mid 80’s.  They like plenty of cover like plants and caves, and will be perfectly happy scavenging leftover flake food and algae.  Ghost Shrimp can be housed in groups or singly in smaller tanks, and they can be housed with peaceful community fish, particularly small tank mates like tetras, rasboras, and other non-predatory fish.

Amano Shrimp

Amano Shrimp, sometimes offered as Japanese Marsh Shrimp or Yamoto Numa-Ebi, were introduced and popularized by Takashi Amano, whose planted aquaria are world renowned.  These little shrimp are about 2 inches at maturity, and are prized by aquarists with planted tanks for their algae-eating habits.  Algae and decaying plant matter is their primary diet, though as with most shrimp, they will greedily eat flake food when offered, and may eat some soft plants like java moss if algae is in short supply.  They are attractive shrimp, with light brown bodies and a tan stripe down the middle of the back.  They have reddish-brown markings along their sides.  They are relatively long lived, and absolutely safe in community environments.
Amano Shrimp are not tolerant of ammonia, nitrate, and nitrite levels, and the aquarium housing them must be well maintained.  They prefer a Ph of 6.0-7.5 and temps from the high 50’s to the high 70’s.  If your algae issue is significant, feed flakes sparingly to steer them to the soft algae.  They will not be successful with tougher algae like spot algae and the infamous Black Brush Algea.

Thanks for the great article Patty,

Until next time,

Dave

 

Surprising new information about aquatic invertebrates is uncovered every day…the following is a small sample, which I’ll add to from time to time.  Please see Part I of this article as well.

 

Good and Bad Pets

The venom of the tiny blue-ringed octopus, Hapalochlaena maculosa, is one of the most toxic known, with the amount delivered in a single bite being sufficient to kill an adult person.  Yet this creature occasionally appears for sale in the pet trade – learn to identify and avoid it!

 

Giant water bugs (Family Belostomatidae) can be collected throughout the USA and make interesting, if aggressive (they can inflict a painful bite), aquarium subjects. The males of many species carry the eggs about on their backs.  A species I collected in Venezuela topped 4 inches in length, and regularly consumed small frogs.  Another I came across at Japan’s Kaiyukan Aquarium easily subdued a 3 inch long minnow.  Please look for my future article on aquatic insects.

 

Most corals rely upon minute creatures for their food and are difficult to maintain in aquariums.  However, tooth coral (Cynarina spp.) accept pieces of shrimp and other large food items, and should be considered as a first choice by those new to coral-keeping.

 

Jellyfishes are not usually available in the pet trade, and are quite delicate in captivity.  One exception is the upside-down jellyfish, Cassiopeia andromeda.  In contrast to all others, it rarely swims but rather rests in a “head down” position, with the tentacles trailing above.  Given intense lighting (it relies upon symbiotic algae) and plenty of brine shrimp, it often thrives in the aquarium.

 

Catching and Storing Food

Surprisingly, some spiders have adopted an aquatic lifestyle, and several of these adapt well to aquarium life. North America’s fishing spiders, Dolomedes spp., float on the water’s surface and dangle a leg below to lure small fish within reach.  The European diving bell spider, Argyroneta aquatica, takes aquatic life a step further – it lives in a submerged, air-filled retreat from which it launches attacks on passing fish and invertebrates.  Please look for my future article on these unusual creatures.

 

Several crabs have interesting ways of “planning for the future”.  Atlantic spider crabs, Libinia emarginata, stuff marine algae into crevices on their shells, effectively camouflaging themselves and storing food at the same time (those I have kept abandon this habit when they reach 3 inches in size).  The ever-popular arrow crab, Sterorhynchus seticornis, impales bits of food, to be consumed in the future, on the pointed end of its carapace.

 

How Big…How Old?

Crabs, lobsters and their relatives (Order Decapoda) are among the most important aquarium and food-trade invertebrates.  The legs of the Japanese spider crab, Macrocheira kaempferi, the largest of the group, may span 13 feet.  Both it and the American lobster, Homarus americanus (at 60+ pounds, the heaviest Decapod) may live for 100 years. The largest freshwater species is the 9 pound New Zealand crayfish, Astacopsis gouldi.

 

At 4.5 feet across and up to 750 pounds in weight, the South Pacific’s giant clam, Tridacna gigas, is the largest of the world’s 6,000+ bivalves (clams, oysters and relatives).  It relies upon commensal green algae for much of its food, and produces the world’s largest pearls – one of which weighed in at 14 pounds!

 

Many mollusks (snails, clams and their relatives) lay down growth rings, which appear as irregularly-spaced lines on the shell.  Much as with trees and turtles, these lines can often be used to determine these creatures’ ages.

 

 

Defense and Survival

Although largely aquatic, several species of North American crayfish, known as chimney crayfish, exploit terrestrial habitats.  They live in wet meadows and dig tunnels, which may exceed 10 feet in length, to the water table.  Recently, it was discovered that these water-filled retreats provide vital breeding sites for salamanders during droughts.

 

Sea urchins are interesting aquarium inhabitants, but most aquarists find them rather unresponsive.  However, they react immediately to the shadow thrown by a hand or other object passing overhead by orienting their spines towards the disturbance.  This is a defensive reaction, designed to direct the sharp spines towards an oncoming fish or other predator.

 

I look forward to hearing about your own observations concerning aquatic invertebrates, and to answering your questions.  Thanks…until next time, Frank.

 

A great deal of interesting information concerning marine, fresh water and terrestrial in invertebrates of the Pacific Basin is available at the following web site:

http://pbin.nbii.gov/marinverts/index.asp