That Fish Blog – Aquarium Advice and Information

Brandon here. Some of my favorite saltwater organisms are the pistol shrimp. There are several hundred species of these shrimp found throughout the world. They are not only found in tropical reefs but closer to home. I have heard these little guys snapping away in muddy areas right offshore in Virginia. Despite the characteristic that gives these creatures their name, snapping shrimp are usually peaceful little critters and interesting additions to a reef tank.

Pistol shrimps belong to the family Alpheidae. They are characterized by their one large claw responsible for the snapping sound they produce. These shrimp are usually known for their mutualistic relationship with certain gobies. The shrimp will dig and tend to a burrow in a sandy or muddy substrate while the goby stands guard at the entrance, watching for prey and predators. The shrimp will even close the entrance to the burrow at night to keep predators out. There are also colonial species of shrimp that live in sponges, somewhat like ants in an anthill.

What makes pistol shrimp fascinating is their enlarged claw. The closing of the claw in itself does not produce the snapping sound. Rather there is a groove in the claw which channels water out as it closes. The water is forced out at around 60 miles per hour. This speed produces an area of low pressure and forms a bubble. When the bubble collapses, intense sound, heat, and even light are produced. This is where the snapping sound that we hear comes from. Temperatures of about 5000 degrees Kelvin, or about 8500 degrees Fahrenheit, can be reached. This blast of pressure is enough to kill small fish and invertebrates. The snapping shrimp is considered one of the loudest creatures in the ocean, and large colonies of them are loud enough to white out the sonar of submarines.

To give you a better idea of what this all looks like (or just to see a shrimp get blasted) watch this video:

Until next time,
Brandon

They came from foreign waters. With stealth, appetite, and agility on their side, they’ve become one of the most successful invasive species in recent history, and realistically, the invasion has only just begun. Their deadly and dizzying beauty is of little consolation to those following the invasion of the Volitan Lionfish.
About a year ago, Dave posted a blog on lionfish as invasive species and the responsibility of aquarists to not release non-native species into waterways. Brandon has followed up with similar articles on some other invasive non-native species, too. Just this week I came across 2 more recent articles about the lionfish invasion, this time about populations established in the Caribbean and off the coast for Florida. I wanted to bring you the articles and an update, as the problem is only getting worse as we could have predicted.

Both articles pinpoint the beginning of the problem as six specimens that escaped into open waterways from a Miami waterfront aquarium that was smashed during hurricane Andrew in 1992, though it is highly likely that there were other contributions, too. It is becoming a serious concern as the predators multiply, their numbers in the thousands, and devastate native populations. The articles liken the invasion to a plague of locusts. NOAA studies show that the populations in some areas have increased tremendously, from 22 per hectare in 2004 to 200 per hectare in 2008. The predators are having a huge effect on commercial fish populations and populations of herbivores that keep algae and other marine vegetation at bay, especially on reefs.

As the drama unfolds, it really is compelling to read about, and it will be interesting and scary to see what will happen in the next couple of years if there are no solutions found to keep the populations in check. Scientists are scurrying to find natural predators of lionfish to aid in control, and they’re encouraging fishermen and restaurants to utilize them as entrees. It’s open season on these fish in many places, but with such huge numbers and range, the outlook is bleak for control…disturbing on so many levels.

http://blogs.thatpetplace.com/thatfishblog/2007/11/07/invasive-species-volitan-lionfish/
http://www.timesonline.co.uk/tol/travel/news/article4538370.ece
http://www.timesonline.co.uk/tol/travel/news/article4538370.ece

Until next time, Patty

Eileen here. Most aquarists have a virtual library of books, websites, magazine, and forums that we like to help identify new fish and invertebrates. I have 5 books on my own desk here and at least a dozen website bookmarks to reference and cross-reference our new arrivals and “unknowns”. Earlier this year, a new website joined those ranks for quick coral identifications. Now that same website has gone even farther and included saltwater fish in their online guides.

Coralidea.com  is the product of Jake Adams and his decades of aquarium experience. The coral guide has 17 categories, including clams and anemones, and can be downloaded at no charge from their website. Unlike some field guide-style identification books, most of the pictures in this guide were taken in aquariums, under aquarium lighting, and of specimens that can actually be found in aquariums. Best of all, the guide can be downloaded onto most mobile devices as well as your computer desktop. Just think – instead of lugging a book to your local fish store, you can just take in your iPod to help you identify the new corals in their tanks.

Now, as of October 8th, Coralidea has officially launched Fishidea, their new saltwater fish identification guide. While not as complete as some of the common books available, Fishidea has the most common saltwater fish (as well as some downright rare species) listed in 18 categories. Unlike Coralidea, Fishidea has species information listed for most of its entries, including hardiness, compatibility, size and diet.

Both Coralidea and Fishidea are considered “works in progress” on the website and the website itself is increasing in functionality as Jake and crew add the photos directly to the site for viewing. These guides are a great way to take a reference with you and its another great addition to the “libraries” of many of our staff biologists and aquatics staff. Besides that, there are just some really great pictures. Don’t forget to download some of their wallpapers while you visit the site!

Eileen

Jose here. Madagascar is the world’s fourth largest island, about the size of Texas or France, and has been isolated from the African mainland for over 160 million years. Madagascar is home to more than 250,000 species of which 70 percent are found nowhere else on the globe.

The first time I came across anything from that country was when I first saw a day gecko and thought wow the colors were amazing. And it wasnt until I came across my first Bleekeri at a cichlid show that my eyes were opened to the livestock of that great country. The fish was pushing maybe 11 inches in a 29 gallon and trying to attack anyone that stepped up to the tank. I needed one!!! I eventually got my hands on one, yay fun times. Spartacus ( yes i named him, later found out it was a her.. oops) in 1 year grew to 8 inches and was a pure terror to me, attacking my hand every time it was in the aquarium.

Now I wanted to breed these fish and as luck would have it she had passed away while I was on vacation. So back to Africans I went. Wasn’t maybe a year later that we got in some Paratilapia
Polleni: the small spot. I purchased 3, 2.5 inch fish for my 40 breeder – 1 dominant male, 1 female and a
younger male. The water conditions were ph 7.6, general hardness of 12 degrees and a carbonate hardness of 8 degrees, with a temperature of 78 degrees. They acclimated very well eating that same night. Their diet consisted of nightcrawlers, marine flakes, krill and marine pellets. The less dominant male was found dead 3 days later and the young pair had started hanging out in an ornamental tree trunk. After about a month and a half the male started becoming very aggressive: not so much with the female but with me. After some time of watching him attack my hands, the female caught on and joined in on the fun: sometimes attacking him, who was double her size.

Now here is where my hate relationship begins. At 6 months the male was a little over 7 inches and the female was close to 4 inches. Then came the day I was waiting for: their breeding tubes were displayed and they were both cleaning the top of a rock. Three days later they had laid what looked like about 200 to 300 eggs. The eggs were not laid on the rock like normal Central or South American egg laying cichlids, these eggs were pinkish orange in color and hung on a string which resembled mini grapes in a clump. The male and female’s aggression stepped up to a new level. And now begins the hate. I tried to take pictures of the parents and eggs and each time I did the male would look at me once and turn around and start eating the eggs. I thought nothing of it as it was their first spawn and I was just happy they bred. The second and third times both happened as I was heading to cichlid shows, and while I was away my girlfriend at the time kept an eye on them. They never once bothered the eggs while I was away, but when I got back and I looked in the tank there went the male eating the eggs again, a slap in the face. They never bred again after that. We shortly moved then and in the move I lost both fish. Temperature change was the culprit as it was 2 or 3 in the morning in October. It will be a while before I keep them again but I know I will. In closing they are fun and anyone who have kept Centrals will enjoy Madagascars.

Until then have fun with Cichlids!

 Jose

Patty here. I received a link to this article from a friend, and instantly thought it would be terrific to share. It features some amazing photographs of thousands of Cownose Rays migrating through the Gulf of Mexico to feeding grounds. Migrations like this happen biannually throughout the animal world, whether birds, mammals, butterflies, or these majestic rays, I’m always awed by the magnitude. These photos are amazing, and they make me feel really small, I mean imagine being surrounded by 3000 or so rays with up to a 6 foot “wingspan” WOW! The article made me remember that with all the economic, political and social turmoil in the world, life goes on seemingly without a hitch out there, just like it has for eons

To read the original article and view more pictures check out: Stingray Migration