That Fish Blog – Aquarium Advice and Information

Please welcome back Desiree Leonard to That Fish Blog.

We as biologists at times take our knowledge for granted and forget that not everyone that is involved in the hobby is fully aware of all of the natural processes and progressions which occur in a saltwater aquarium.
Frequently we are contacted by frantic new aquarists with the following:  “I have little bug – like things crawling all over the rock in my saltwater tank.  I swear they weren’t there before.  What are they and where did they come from? Are they going to make my fish sick?  How do I get rid of them?”

Well, after talking the caller down off the ledge (so to speak), I give this answer:

In all likelihood, these are Amphipods and Copepods; shrimp-like crustaceans that dwell in the substrate and rocks.  Because of the thousands of species contained within these groups in Class Crustacea, I am not going into detail about the taxonomy of these organisms, but here are some basic facts about these tiny crustaceans.
• There are both pelagic (free swimming), and benthic (bottom dwelling) bugs.
• Copepods occur in all types of aquatic ecosystems; freshwater, estuarine (brackish) and marine.
• Amphipods are mostly found in marine ecosystems, but there are some freshwater and terrestrial species.
• They are just a few of the tiny animal organisms that make up zooplankton, which contributes to the overall make up of plankton.
• These creatures eat phytoplankton (tiny plants and algae that also help make up plankton), small microzooplankton (the division of zooplankton that are smaller than 200 microns, or 1/127th of an inch in size), and detritus.
• Only a few of the thousands of species of copepods and amphipods known are carnivorous or parasitic, and these are rarely found in a saltwater aquarium system.
• For many saltwater fish and other marine species, copepods and amphipods are a primary food source, both in nature and in captivity.
• Because these tiny organisms are a natural part of the plankton food chain in the ocean realm, they are naturally going to occur in a saltwater aquarium environment. They are also micro-cultured as food for various species of adult marine animals, as well as used and tested as a food source in the research of culturing and rearing all kinds of tank-raised fry.
• Copepods and amphipods most often appear in closed aquarium systems after live sand and/or rock has been added.  They will “bloom” in the tank when the temperature is slightly warmer and a food source is available.

Another critter that may be seen is the isopod.  Also called pill bugs, fish lice and rolly-pollies, these animals are found in all parts of the marine environment.  Most isopods are free living and harmless, feeding on detritus and algaes, however, some are predatory, or parasitic, and dangerous to other reef aquarium animals.

How did these “pods” get into the tank?  Well, they’ve most likely been there for a while, just not in numbers large enough to notice.  These organisms are microscopic or plankton sized when they start out, so until they grow large enough to be seen with the naked eye, you don’t know they are there.   They hitchhike in on live rock and sand, and it is only after you have placed it into your aquarium that these organisms crawl out and make themselves at home.

If you have a large population of “pods” naturally, count yourself among the lucky few.  Many aquarists go to great lengths to create a large healthy population in either their tank or refugium.  Remember, these “bugs” are a natural part of a healthy aquarium ecosystem, as well as an important food source required by some species to survive.  In most cases they won’t hurt anything.  You shouldn’t have to do anything about them.  If you are concerned however, you can provide a natural predator which should keep the population under control.  Here is a list of species which pick at live rock, or sift substrate in search of these tasty morsels.  Keep in mind those fish marked with a * are species which feed on these bugs as their primary food source.  They are challenging to keep, requiring a well established aquarium with a consistently high “pod” population to live on lest they starve.  Keeping more than one of these obligate “pod” eaters in a tank will most likely lead to a depleted food source.
• *Mandarinfishes/Dragonets; Synchiropus splendidus Blue/Psychadelic Mandarin, Synchiropus picturatus Green/Spotted Mandarin, Synchiropus stellatus Red Scooter/Starry Dragonet
• *Sand sifting gobies; Valenciennea spp. Sleeper Gobies, Signigobius biocellatus Twinspot/Signal Goby
• Most Firefishes are planktivores which may occasionally pick these bugs from the rock.
• Most Angel, Butterfly, Hawk, and Wrasse species spend their days grazing on fauna found on the rocks, however, do not consider this as a primary food source – merely an opportunistic treat.
• Seahorses feed primarily on these “pods” but are not a beginner fish and should not be housed with other fish.
Amphipods, copepods, and isopods are just a few of the fun little hitch-hikers we get questioned about, and we enjoy helping our customers with identification issues.  If you should have other fun things pop up in your ecosystem, here are some other things you can do to help identify them:
• Buy some good invertebrate identification books for your saltwater reference library.
• Refer to marine invertebrate database and profile information, as well as photo galleries.
• If you have a personal saltwater Web site, create something like a “Can You Help Identify This?” page. You can display photos here and allow visitors to email back to you about them.
• Post a message in various aquarist forums asking for help with identification. If possible include a photo of good clarity, or provide a link to a Web page you may have created as described above.

*Photo Emailing Tip: When you email a photo to another aquarist asking for help with identification on something, be kind. Only send an image that is reasonably sized, and is clear enough to tell what you want identified including a “brief” description.

Thanks,

Until Next Blog,

Desiree

Introduction

A thorough understanding of how water quality affects animal life is essential if one is to be a successful aquarist.  This is sometimes a bit difficult for beginners to accept, but please remember that it is a serious mistake to spend time learning about the habits and dietary needs of aquatic creatures while ignoring the “less glamorous” aspects of the hobby.  Once you understand water chemistry basics, your appreciation of how fishes and invertebrates survive in their environments will be heightened. 

The Nitrogen Cycle

The nitrogen cycle is a critical factor in the establishment of a crystal clear, well-balanced aquarium.  Poor functioning of the nitrogen cycle is undoubtedly the most common reason behind new aquarium failures.

Basically, the nitrogen cycle is a process by which nitrogen is converted to other organic compounds that are then utilized by plants and animals as food.  Nitrogen enters the aquarium via dead animals and plants, uneaten food, and the waste products of fish and invertebrates.  The most toxic nitrogenous compound that is added to aquariums in this manner is ammonia.  Ammonia occurs in two forms, ionized and un-ionized, with the un-ionized type being extremely toxic to aquatic organisms.  The proportion of the total ammonia that is un-ionized rises as the water’s temperature and alkalinity increases.

Bacteria and the Nitrogen Cycle

Two types of bacteria control the functioning of the nitrogen cycle.  These bacteria are aerobic, which means that they require oxygen in order to survive.  Bacteria populations develop and thrive on substrates that are exposed to oxygenated water, such as gravel and the filter pads and carbon within filters.

The process by which aerobic bacteria convert ammonia to less harmful compounds occurs in two phases. Nitrosomas bacteria convert ammonia to compounds known as nitrites. Nitrites, while dangerous to aquatic organisms, are less toxic than is ammonia.  In the second stage of the process, bacteria of the genus Nitrobacter utilize these nitrites as food, and in doing so convert the nitrites to nitrates.  Nitrates are the end product of the nitrogen cycle, and are the least toxic of the compounds involved.

Nitrogenous bacteria (the name given to the various species of bacteria that feed upon ammonia-based compounds) exist in huge populations in natural water bodies and in healthy aquariums.  Until such are established in your aquarium, its levels of nitrogen-based compounds will be toxic to nearly all fishes and invertebrates.

The time it takes for healthy populations of nitrogenous bacteria to become established in an aquarium is often referred to as the “conditioning period”. Its actual timetable varies greatly depending upon the unique characteristics of each aquarium and of the animals therein, but usually falls in the range of 1-6 weeks.

Please bear in mind that water clarity is not an indicator of the functioning of the nitrogen cycle.  The only sure way to monitor the cycle is via frequent testing of the water to determine the levels of ammonia, nitrates, and nitrites (please see below).

Altering the Nitrogen Cycle

Your aquarium’s conditioning period may be shortened by the addition live aerobic bacteria.  I have had good experience with Biozyme Freshwater and Biozyme Saltwater, and strongly urge you to use either with all new aquariums.  Products such as Coral Vital LSB Pro, which accelerates the growth and reproduction of bacteria in marine aquariums, should also be considered.

You can also help the process along by adding filter material from a well- conditioned, parasite-free tank into the filter of your new aquarium.  Natural materials such as “live rock” and “live sand” also host beneficial bacteria and offer another option.

In the past, it was standard practice to use hardy fish, such as domino damselfish in marine aquariums or guppies in freshwater aquariums, to hasten the conditioning period (their waste products started the process and provided food for bacteria).  However, additives such as those mentioned above are more effective and infinitely kinder, as many of the fish subjected to this process did not survive.

When cleaning your filters, always retain a bit of old filter medium (carbon, floss) and add this to the clean filtering material.  In this way, you will introduce aerobic bacteria into the newly-cleaned filter.  These will reproduce rapidly and greatly increase filtration effectiveness.

Please be aware that the addition of packaged bacteria does not eliminate the need for a proper conditioning period. Water quality must still be monitored carefully, and animals should be introduced to the aquarium in small numbers. 

Measuring the Levels of Nitrogenous Compounds

The frequent use of test kits is essential during the aquarium’s conditioning period, and on a regular basis thereafter.

Ammonia should be tested daily until you notice a sudden decrease in its level.  This decrease signals the presence of Nitrosomas bacteria.  Nitrate levels will then follow the same pattern, as the Nitrobacter bacteria become established.

The conditioning period may be considered at an end once the nitrate levels drop substantially.  You may now begin to introduce fish and invertebrates into their new home.  Be sure to add animals in small quantities, so as not to overwhelm the nitrifying potential of the bacteria present, and observe them carefully for signs of stress.

The pH level should be checked often as well, since the water may become acidic during the conditioning period.

I am very interested to hear about your successes and challenges in establishing new aquariums, and will be sure to pass along your information to my readers in future articles.  Thanks, until next time, Frank.

An interesting technical article on the role of nitrogenous bacteria in natural marine habitats is posted at:

http://aem.asm.org/cgi/reprint/60/5/1554.pdf

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

Knowing where to start and stop when it comes to writing about invertebrates is a real problem – any single group could keep one occupied for a lifetime. Today I’d like to highlight some interesting facts concerning a few commonly kept types and their relatives. I’ll add to this from time to time.

General
Invertebrates (animals without backbones) account for approximately 97% of the world’s animal species, yet we have no idea of their total numbers. The smallest are invisible to the naked eye while the largest, giant squid, may exceed 60 feet in length.

Nearly every injectable drug manufactured in the USA is tested for bacterial contamination with a chemical extracted from horseshoe crab blood (synthetics do not work as well). Several states are restricting the collection of these animals (often used as fertilizer!) and requiring that they be released after blood specimens are taken.

Invertebrates have colonized every habitat imaginable, from freezing Antarctic seas to the boiling hot water of geysers. The sponges, crabs, tubeworms and others living near deep sea vents form the only animal community that does not rely upon photosynthesis as the basis of the food chain (bacteria that consume methane function as “plants”).

Despite being a creature of legend for centuries, the giant squid, Architeuthis sp., was not captured on film until 2004. Two years later, the same Japanese scientists that filmed the animal caught a specimen on a fishing line, thus giving the world its first view of a living giant squid.

Eating and Being Eaten
Despite radically different appearances, jellyfishes, sea anemones and corals are closely related (Phylum Cnideria). All gather food and excrete wastes through a common opening, and overcome their prey with stinging cells.

Jellyfish, although comprised largely (95%) of water, are able to snare prey as large as small fishes. Surprisingly, they form the bulk of the diet of many huge sea creatures, including the world’s biggest turtle, the leatherback.

The dried krill (shrimp-like creatures of the Class Brachiopoda) that you may use as fish food form the basis of the food chain in most of the world’s oceans. Also, a number of surprisingly large creatures, including whales, manta rays and basking sharks, rely upon krill as their primary diet, consuming billions each day.

Although viewed by most as sluggish creatures, many of the world’s 70,000+ species of snails and slugs (Phylum Mollusca) are quite effective predators. Various types pry open or drill through clam shells and cone snails impale fish by shooting out barbed tongues. Certain sea slugs consume anemones and incorporate the stinging cells into their own gill tufts.

Reproduction
Australia’s Great Barrier Reef, the world’s largest, is 1,250 miles long. Somehow, its untold billions of individual coral animals synchronize reproduction so that the sperm and eggs of all are released into the sea at the same time.

Banded coral shrimps, Stenopus hispidus, form long-term pair bonds, and males have been observed to share food with gravid (pregnant) females. The eggs, which are glued to the females’ swimmerets (feathery structures below her abdomen), are aerated and protected by her. Upon hatching, however, the young may be consumed by both parents!

Surviving
Sea cucumbers make interesting if occasionally unsettling aquarium inhabitants – when disturbed, they discharge their stomachs through the anus! Amazingly, these sea star relatives can regenerate the discarded stomach.

The unique tube feet of sea stars (Phylum Echinodermata) function in locomotion, respiration and as sensory organs. Water-filled canals linking the feet can, via a series of valves, build up enough pressure to enable sea stars to pry open clam shells (try that with your hands!).

The anemone hermit crab, Parurus prideauxi, places a stinging sea anemone on its shell as protection and camouflage and re-locates it when changing shells. The anemone, in turn, gets a safe anchoring place and, perhaps, access to leftovers from the crab’s meals.

Using Invertebrates – Now and Then
Over 10,000 species of sponges (Phylum Porifora) inhabit both fresh and salt water. Several types have been collected from the Mediterranean Sea since ancient times. After drying in the sun, their fibrous structural tissue (spongin) made an excellent bath sponge.

Horseshoe crabs (Phylum Chelicerata) are among the world’s most ancient creatures and have remained relatively unchanged for over 300 million years. Closely related to spiders and not crabs at all, small specimens make interesting additions to a marine aquarium.

And, Finally…An Odd Personal Tale
Octopuses (Class Cephalopoda) are the most intelligent of the invertebrates and make fascinating aquarium subjects. They are also quite well-sighted – one I kept would, according to my grandmother, “stare” at her while she worked in the kitchen. Not wishing to upset my beloved pet, she covered its tank when preparing octopus for dinner!

Well, only a few billion more facts to go! I’ll continue next week, and periodically after that. As there are so many possibilities, I would greatly appreciate your suggestions concerning invertebrate-oriented subjects that you may wish to learn more about. Thanks, until next time, Frank.

You can learn a great deal about invertebrate biology at the web site of the Australian Museum:
http://www.amonline.net.au/invertebrates/ara/index.htm

First of all, Red Sea makes a kit for almost anything a hobbyist could desire to test for. They have test for standards such as ammonia, nitrite, and nitrate, to reef kits such as pH, alkalinity, calcium, magnesium, and phosphate, to ones for more obscure parameters like silica, dissolved oxygen, and residual ozone. Red Sea also makes a full range of test kits for freshwater, as well, including important tests for freshwater planted aquariums like carbon dioxide, iron, and both general hardness and carbonate hardness. To do them all justice would take pages and pages, but I want to point out a few test kits and their particulars that might not be as well known or recognized yet.

I have written and given presentations on marine fish diseases extensively. Inevitably the use of copper comes up. One drawback to using copper is certain test kits only accurately report the values of certain formulations of copper, so one must take special care to properly match the test kit with the medication being used. Red Sea eliminates that confusion by packaging both the copper test kit and the medication in one box for ready-made use. This falls in line with Red Sea’s motto of “making it easy”. By the way, the copper medication (Paracure) is also available individually for those that require additional copper for dosing larger tanks or for repeated usage.

Most titration style test kits, such as those for calcium, usually tell the hobbyist to watch for a color change from pink to blue. But, Red Sea goes a step further by including a color chart with their titration test kits which demonstrates both the starting and ending colors so the user does not have to guess which shade of blue is the proper end point of the titration.

With the color matching style of test kits, those in which the hobbyist must match the color of the reagent in the vial to a color bar, Red Sea has gone to great lengths to make their tests have very distinct color changes. Some other brands of test kits I have used have color bars that change from yellow, to darker yellow, to still darker yellow, to yellowish-green, to green with a hint of yellow. Very much ever changing shades of grey which make accessing parameter values somewhat difficult. Red Sea’s tests have very dramatic color changes which provide easy to interpret results.