Lightly Salted

January 11, 2018. My last post was over 7 years ago, and while it doesn’t seem like it’s been that long, the dates don’t lie. A lot has happened since August, 2010. My wife and I welcomed our son into our family about 7 months after my last post. We bought a house a couple years after that. Our son was diagnosed with autism spectrum disorder. I changed jobs twice. In other words, life happened. And it’s been good. My brackish aquarium? Well, it was torn down. But my fascination with brackish environments has not diminished, so my latest project is converting a 40-gallon aquarium to a brackish riparium. If all goes well, I have other aquarium ideas in the works. I will record and update my progress here. As for the blog, I hope to return to exploring topics relevant to brackish aquarists. I have updated the links that had become broken at some point in the last seven years. That’s it (for now). Let’s keep it a little salty!

August 26, 2010. The August 2010 issue of Practical Fishkeeping has an interesting article recounting Heiko Bleher’s journey to Iran in search of Iranocichla hormuzensis , one of the few cichlid species found in Asia. Like many cichlids, this species tolerates a range of temperature and salinity. Unfortunately, I. hormuzensis is critically threatened with extinction, primarily due to loss of habitat. Bleher records that several localities where the fish had previously been collected were now completely dry; of those that remained, Bleher notes that dessication appears to be gradually increasing the salinity to levels beyond the tolerance of even this adaptable cichlid. This is unfortunate, as I. hormuzensis is perfectly suited to a light brackish aquarium environment. As it is the easternmost-ranged member of the African cichlid flock (the three Etroplus sp. of India are related to the Madagascan group of cichlids), I. hormuzensis is a species of special concern. Of course,...

April 3, 2010. Laguna Alchichica (Lake Alchichica) is a deep maar lake (a type of crater lake) in central Mexico, and what makes Alchichica interesting is that it is a hyposaline alkaline lake. Researchers Oliva, Luger, Alcocer, and Cantoral-Uriza, in their survey of Cyclotella choctawhatcheeana (a diatom found in Lake Alchichica), note that the lake’s water is composed of 8.3-9 grams of dissolved salt per liter with an average pH of 8.8-10. Seawater has approximately 35 grams (1.2 oz) of dissolved salts (mostly, but not entirely, the ions of sodium chloride) with a pH of 7.5-8.4 (source: wikipedia ). Though not saltier than the ocean, as some believe, Lake Alchichica is still quite saline considering the endemic fauna found within its waters, namely the brackish salamander Ambystoma taylori . It is also home to both an endemic silverside fish, Poblana alchichica , and an endemic copepod, Caecidotea williamsi . Ambystoma taylori , or Taylor’s Salamander, is an amazing amphibian....

April 1, 2010. After consulting the late Robert Rush Miller’s book Freshwater Fishes of Mexico , I can report than none of the Xiphophorus species found in Mexico naturally occur in brackish environments. The ancestors of the aquarium platy, X. maculatus and X. variatus , are found near the coasts and, as such, might occasionally venture into brackish waters, but I could not find any record of this in the aforementioned book. The closest brackish-inhabiting Xiphophorus I could find was X. andersi (the Spiketail Platy), inhabiting waters with 0.3 ppt salinity, but this is technically still considered freshwater (according to my reading). So, while this doesn’t rule out the Xiphophorus species south of Mexico, it does suggest that this particular grouping of fish species do not naturally inhabit brackish waters.

March 31, 2010. In my previous blog I mentioned that one of the Blue Platies in my brackish aquarium had given birth (and the babies seem to be doing fine). Xiphophorus sp., such as platies and swordtails, are frequently kept in brackish aquariums (although the water in these aquariums typically has a specific gravity below 1.005). However, it is important to remember that Xiphophorus species are usually found in freshwater habitats; their adaptability to brackish conditions is more a demonstration of their hardiness and preference for waters with a higher pH. Since most brackish aquariums (using a quality marine salt to achieve the desired salinity) also have a higher pH, Xiphophorus species generally adapt fairly easily (and, like many poeciliids, my Blue Platies love feasting on the algae that grows so readily). Other poeciliids, such as mollies and guppies, naturally occur in brackish (and even marine) environments, so these would be better choices for aqauriums with higher sali...

March 31, 2010. About an hour ago, one of the aquarium strain Xiphophorus maculatus 'Blue Platy' females gave birth to 12 babies. There might have been more, since platies in confined spaces (like breeder traps) will eat their own young, but 12 is enough for the time being. Usually the Orange Chromides eat the young, but this time I was able to seperate the mother out from the other platies, placing her in a breeder trap last night. It was the Orange Chromides’ behavior that clued me in to the fact that the mother had given birth: I was looking at the aquarium from across the living room as my wife and I ate dinner, and as I watched I saw one of the chromides throw itself against the side of the breeder trap. Knowing the Orange Chromide’s fondness for fish fry, I decided to check the breeder trap. Sure enough, there were baby fish. Exciting! An Orange Chromide watches two Blue Platies foraging for  algae on an unknown Cryptocoryne sp. Photo by D. Jury.

March 29,2010. The Bermuda Islands possess but a handful of freshwater lakes and ponds. On the main island of Bermuda, the largest bodies of water are Mangrove Lake and Trott’s Pond, both on the east end of Bermuda Island near Harrington Sound. There are also two marshes/ponds near the center of the island, Pembroke Marsh and Warwick Marsh (also called Warwick Pond), and another pond, Evan’s Pond, located on the western end of the island. Finally, there is Walsingham Pond, a sinkhole created when a cave collapsed, but this is essentially seawater; the tidal flux and the organisms inhabiting this pond indicate that there is still a link to the ocean. On nearby St. George’s Island there is a small pond, Lover’s Lake. Of course, these are freshwater only in that they are not directly connected to the ocean — most of Bermuda’s ponds are brackish, if not seawater, although Warwick Pond is reported as “close to being freshwater” according to Dr. David Wingate (as reported by Craig Morfitt ...

March 25, 2010. According to the online Encyclopedia of Earth article “Biological diversity in the Caribbean Islands” , the Caribbean Islands are home to “more than 160 freshwater fish species, about 65 of which are endemic to one or a few islands, and many of these to just a single lake or springhead. As in other island hotspots, there are two distinct groups of freshwater fishes in the Caribbean: on smaller and younger islands, most fish are species that are widespread in marine waters but also enter freshwater to some degree, while on the larger and older islands of the Greater Antilles, there are several groups that occupy inland waters, including gars, killifishes, silversides and cichlids.”

March 23, 2010. Earlier today I stumbled across a post on one of the many online fishkeeping forums where an aquarist asked if there were any small freshwater fish from the Caribbean islands that would be suitable for a community aquarium. Only one person had replied, stating that only saltwater fish were found in the Caribbean. This, of course, is incorrect. In fact, one of the most popular species of aquarium fish is native to several of the islands (as well as mainland South America). If you haven’t already guessed, that fish is  Poecilia reticulata , also known as the guppy. It is probably the guppy’s adaptability and preference for alkaline environments (a trait common to most poeciliids) that has allowed it to disperse across the Caribean. Poeciliids, as members of the cyprinodonts, are believed to be a secondary freshwater fish family – in other words, their ancestors were originally marine and they adapted to colonize freshwater environments. This includes anothe...

March 20, 2010. This is my first post, and, as such, I must tout the best reference book for the brackish aquarist…period. If you haven’t perused (or perhaps purchased) a copy of Brackish-Water Fishes: An Aquarist’s Guide to Identification, Care & Husbandry (published by T.F.H. Publications, Inc., ISBN-13 9780793805648), then do so. Edited by Neale Monks, this volume is well-worth the purchase price, even if several of the fish covered in the volume are rarely (if ever) available. For the brackish aquarist, this book helps paint a more complete picture of the estuarine and mangrove environments; also included are chapters specifically on Etroplus maculatus (the Orange Chromide), the “freshwater” moray eels and other eel-like fish, and the various pufferfish species most suitable for brackish aquariums. If you want to get a feel for Neale Monks’ expertise, check out his website in the links section of this blog, or just click here . His is one of the first sites (and, of cou...