Medicines from Sponges and Other Sessile Marine Invertebrates

Hello, Frank Indiviglio here.  The world’s oceans harbor a great many creatures that produce medically valuable compounds. Sessile marine invertebrates (those which do not move, but rather remain fixed in one location) seem to be particularly valuable in this regard.  In fact, sponges, sea whips, sea squirts and similar animals are the source of most of the invertebrate-derived medicines in use today. 

A review of the pharmaceutically active compounds isolated from sessile marine organisms shows that, while the animals themselves are quite different from one another, their shared lifestyle has fostered similar adaptations – the evolution of powerful chemical secretions.

 Protection for Immobile Animals

Animals which cannot flee from predators must devise alternate means of protection…an arsenal of protective chemicals, for example.  Also, the feeding mode utilized by many sponges and other sessile organisms – filtering seawater – brings not only food but also harmful pathogens and parasites into their bodies.  These are attacked with potent antimicrobial compounds.

 A suitable anchorage (attachment) site is vital to the survival of an invertebrate which is unable to move about.  Competition for such sites can be keen, yet immobile animals are again faced with the dilemma of being unable to physically exclude other animals.  Many have, therefore, evolved secretions that kill other animals. The composition and function of these various chemicals often lends them medicinal value as well.

Medically Important Marine Invertebrates

Sponges, the best studied of the marine invertebrates, and have given us Topsentin, an anti-inflammatory, and Lasonolide, which fights tumors by binding with their DNA. 

Brightly colored sea whips have yielded Pseudoterosin, which reduces swelling and accelerates wound healing.  Also known as gorgonians, several species of these soft corals do well in marine aquariums.

Tunicates, or sea squirts, evolved a primitive backbone, known as a notochord, over 540 million years ago, and are thus the earliest ancestors of modern day vertebrates.  These sac-like filter feeders produce Ecteinascidin,   a compound which blocks DNA transcription.  It is believed that Ecteinascidin may someday find use in treating breast cancer. 

Bryostatin, isolated from colonial marine invertebrates known as bryozoans, or moss animals, forces cancer cells to mature, thereby halting their ability to divide.  

A number of mobile marine invertebrates also produce chemicals that are of interest to medical researchers.  Cone snails, for example, secrete virulent toxins that have yielded the powerful pain killer Ziconotide.  This calcium channel blocker inhibits the relay of neurotransmitters and is used to treat people living with severe chronic pain.

Opportunities for Aquarists and Researchers

So, please don’t ignore the small, immobile creatures in your aquarium and the world’s oceans.  Your observations of their behavior can lead to unexpected and medically important discoveries.  For those of you interested in serious medical research, the world’s marine invertebrates offer unlimited possibilities, and the field is wide open.

Further Reading

The Harbor Branch Oceanographic Institution has posted an overview of some of the exciting work being done with medically useful marine invertebrates at http://www.informaworld.com/smpp/content~content=a713743150~db=all.

Please write in with your questions and comments.  Thanks, until next time, Frank Indiviglio.

Algae in Freshwater Aquariums and Ponds: a Primer (Part II)

Hello, Frank Indiviglio here. Please see Part I of this article for information on using plants and bacteria to control algae. Today I’d like to take a look at some algae-eating fishes, snails and shrimps.

Sucker Catfishes (Plecostomus, Hypostomus, Loricarichthys spp.)
An incredible array of fishes consume algae, with these interesting beauties being among the best known. Larger sucker cats and Chinese sailfin sharks (see article below) can also be kept in outdoor ponds.

Thailand Flying Fox, Epalzeorhynchus kallopterus
This nicely marked fish consumes all types of algae, and is also fond of the flatworms that sometimes arrive in aquariums along with live plants.

Siamese Algae Eater, Crossocheilus siamensis
This fish is similar in appearance to other, less-effective species, and is sometimes sold as the “True Siamese Algae Eater”. It does well in schools, and consumes even the coarser varieties of hair and beard algae.

Chinese Hillstream Loach, Beaufortia kweichowensis
This small loach is one of my favorites. It has been compared to a flounder in appearance, but reminds me of the oddly-shaped torpedo rays.

This active loach is adapted to fast-flowing waters, and fares best in high oxygen environments. It is well-suited for removing algae from glass and plant leaves, and is rarely if ever bred in captivity…definitely a fish worth working with for those interested in breaking new ground.

Garra pingi pingi or Pingi Log Sucker, Discognathus pingi
Formerly rare in the trade, this stout East Asian bottom dweller has a huge appetite for algae of all types. Many aquarists find they must supplement its diet with algae wafers; those I have kept took pre-soaked kale as well.

This is another species which would make a nice breeding project, as only wild-caught animals are available at this point.

Algae Eater, Gyrinocheilus aymonieri
The “standard” algae control fish in smaller aquariums, the taxonomy of this interesting species is somewhat of a mystery. While typically reaching 4 inches in length, I recall receiving shipments of individuals that topped 11 inches. I hope to keep some in an outdoor pond in the future, to see if the increased water volume might spur additional growth.

Algae eaters relentlessly comb rocks, glass and plant leaves for algae, and will take leftover fish flakes as well.

Freshwater Shrimp
Almost all of the dozen or so species currently available favor algae as food. Particularly attractive is the cherry shrimp, Neocaridina denticulata sinensis. Given proper care (please see article below) they will breed prolifically, with a large group making for a spectacular display.

Freshwater shrimp will co-exist with the fish mentioned above, but will, however, be harassed or eaten by fishes with carnivorous tendencies.

Snails
A number of snails live almost entirely upon algae, but many consume plants as well. Apple snails can eat a surprising number of plants overnight, while olive Nerites (please see article below) take only algae and do not reproduce in fresh water. The Japanese trapdoor snail is also a good choice, but needs warm, well-filtered water.

Further Reading
To learn more about some of the creatures mentioned above, please see the following articles:
Freshwater Shrimp

The Chinese Sailfin Shark

The Olive Nerite

Please write in with your questions and comments. Thanks, until next time, Frank Indiviglio.

The Cichlids – an Overview of a Fascinating and Diverse Family of Fishes

Hello, Frank Indiviglio here.  Among the Cichlids (Family Cichlidae) we find some of the most interesting and highly desirable of all freshwater aquarium fishes.  Nearly all show a startling degree of responsiveness to their environment and owners, with many becoming true “pets” as opposed to animals to be observed only.  Included among the group are Oscars, Jack Dempseys, angelfishes, convicts and other popularly-bred species, as well as a number about which little is known.

Diversity and Range

With well over 1,300 species named to date, and many as yet un-described, this family is one of the fish world’s largest. Ranging in size from 1 to 36 inches, Cichlids inhabit the fresh and brackish waters of Central and South America, the West Indies, Africa, Madagascar, Syria, Israel, Iran, southern India and Sri Lanka.  One species, the Texas cichlid, occurs in the USA.  Found throughout the drainage of the lower Rio Grande River, it is the most northerly of all cichlids. 

A number have been widely introduced, with Oscars (velvet cichlids) being long-established in southern Florida.  I have collected them in the Everglades, and have reports of a great many other introduced populations.

Parental Care

One near universal trait among the family is the amazing degree of parental care given the young. In many cases both the parents tend to the fry, cleaning them and the nest site and driving off potential predators.  The lovely, popular discus (Symphysodon aequifasciata), a native of the Amazon Basin, feeds its young with a modified mucus secreted from the skin.

The Unique “Second Jaws”

Cichlids have a second pair of jaws in the throat.  Known as the pharyngeal jaws, these unique structures process food and have freed the primary jaws to develop an amazing array of adaptations to deal with specific and unusual food items.  Included in this family are species that feed upon bacteria, other fishes, hard-shelled mollusks, algae and an amazing assortment of other food items. 

It is speculated that specialized adaptations have allowed cichlids to become the dominant fish family in many of the ecosystems in which they occur.

African Rift Lake Cichlids

 In Lake Victoria and other water bodies of Africa’s Great Rift Valley live a variety of cichlids that have all evolved from a very small number of “parent species”.  About 90% of these fishes are endemic to a single lake, and the speciation process seems to have occurred in the relatively short time.  Up to 200 closely related species, often termed “species flocks”, may be found in a single lake. 

I’ll cover the care of individual Cichlid species in the future. Until then, please write in with your questions and comments.  Thanks, until next time, Frank Indiviglio.

Further Reading

We have posted a number of Cichlid care articles on our blog.  For information on keeping the popular and aptly-named Red Terror, please see The Red Terror: Cichlid Species Profile .

Ed. Note: Lots of cichlids are featured on our catalog photo contest located on Facebook.  Take a look here and vote for your favorite.

Building a Paludarium – an Upcoming Winter Project

Patty here.

So, Summer is rapidly passing us by, and before we know it, Fall will be upon us.  I always dread the end of warm days for my plants.  After perfectly sunny and humid days provide them with perfect conditions to thrive, I have to shove the plants into every spare corner and windowsill of the house and pray that they will make it through another long, cool, dry winter.  This year I am especially dreading it, since this spring I invested in several ferns and trailing plants that are humidity loving, like Maiden’s Hair Ferns, and some others that are thriving in moist soil that I fear will not handle the transition to indoors for the long duration.

I think the solution to my problem might be one that I have been contemplating for a while now, the construction of a new Paludarium.  In my last entry, I wrote about Archerfish and the possibility/benefit of keeping them in a large Paludarium.  For anyone who is unfamiliar with the concept of this type of set-up, it is kind of a hybrid aquarium/terrarium with a land area and a water area capable of supporting a variety of plants and also a potentially terrific environment for fish and amphibians.  The set-up ends up looking like a slice of marshland or rainforest, and I think that some of my plants may be in for a winter holiday if I can pull it together for them. 

I actually have 2 spare aquariums to potentially use for this project, an old 55 gallon and a 65 gallon.  The 55 has been used before as a terrarium, but not as a true paludarium as the shallow aquatic side was completely divided from the terrestrial side with a length of plexiglass.  It served its purpose at the time, a green home for a couple of green tree frogs.  The water side was too shallow to keep any fish, but that will be remedied in the new 65 gallon project.

 Before I get started I’ll be doing some rearranging, so the project isn’t going to get off the ground for a while yet.  For now, I’m considering the components I’ll need.  Materials that I have on hand for the project are planting media (soil, flourite, clay pellets), submersible pumps/filters, heaters, lighting (though I may need to upgrade), plants (always on the lookout for more), and some other decor like stone fountains, wood and rock.  I’ll be acquiring or collecting some other materials I’ll need for construction gradually so that I can get set up by the time the weather turns cold.   I’ll need some PVC pipe and fittings some egg-crate, screen or landscape fabric, charcoal, sealant, and some other bits and pieces, maybe some plexi-glass and some cork bark depending on the layout I choose.  Design will be the next step, and the second part of the great paludarium blog.

I’d be interested to hear any ideas from readers who have attempted this before and have some insight. With such creative possibilities here, anything can be helpful.

Check out some interesting paludariums on YouTube.

Until next time,

Patty

“For the record…”: Keeping track of your aquarium

Eileen here. With all of the water changes, filter changes, feedings, testing, supplements and other changes and maintenance we do on our aquariums, it can be difficult to remember what was done and when. Some problems with aquarium systems as well as regular maintenance are dependent on what has been happening with the tanks over time, not just within the very recent past. This is just one of the reasons that make it important to keep a record of the every day maintenance of the system as well as any other events that may have an impact on the health of the fish.

Keeping records of any activity with an aquarium system is not a new idea. Almost every public aquarium keeps records of everything that goes into or out of their water – this is even required by some scientific organizations to keep the aquarium’s certification or grants. Their records and even the records kept by stores like That Fish Place/ That Pet Place are obviously going to be very detailed than the average home aquarist might need, but it is a good idea to take their lead and keep track of your aquarium. You can use a computer program like Excel or Word  if you’d like, or you can simply keep a notepad and pen with your aquarium supplies.

So what should you record? The types of events you should keep track of can be divided into a few main categories: Water Chemistry, Maintenance, and Livestock.

Water Chemistry recordings would be the results of any regular water tests done on your tank (pH, ammonia, nitrite, nitrate, salinity, temperature, etc) as well as the dosages of any supplements or medications you add to the aquarium.

Maintenance records keep track of regular maintenance (water changes, light bulb changes, filter pad changes or cleanings) as well as any out-of-the-ordinary events like a new heater or a malfunctioning piece of equipment.

Livestock records help you keep track of what live fish, plants or invertebrates you are adding to your aquarium and what you are removing from the tank or lose due to deaths or illness. You can also make observations about any unusual behavior you are noticing in the livestock, symptoms of illnesses, what the fish are (or are not) eating, even their sizes from time to time to see how quickly they are growing.

Other events: It is also a good idea to keep track of any other unusual events that may affect your aquarium. Power outages, heat waves, cold spells, and other events that may not have an immediate affect on the aquarium can cause changes in the aquarium a few days or weeks later that can be traced back through your records. Even a houseful of guests can be important to record if it changes the activity around the aquarium or the feeding schedule of the fish.

Getting into the habit of keeping a few notes on your aquarium can make difference in the long run. After all, some of us have a hard time remembering what we had for dinner last week, much less when we last changed that light bulb, when we added that new invert to the tank or how well a certain fish has been feeding! A running record of some of these details can help refresh your memories, as well as keep track of your progress in the aquarium hobby.

Along these same lines, Current-USA offers a free downloadable computer widget to keep track of aquarium maintanance schedules. Working in conjuction with your records, the two together can go a long way toward helping you maintain a healthy system.

Until next time,

Eileen