by Saltwater Smarts | May 27, 2016 | Corals, Fish, Reef, Science, Tanks
Threadfin Cardinalfish (Zoramia leptacantha)Walk by an LFS sales tank containing a few specimens of threadfin cardinalfish (Zoramia leptacantha), and you might not give them a second glance. Chromatically speaking, this species isn’t exactly a showstopper compared to some, especially when viewed in your average LFS environment. But don’t let this cardinal’s unassuming appearance fool you; it can make for an impressive display species when kept in groups. Physical traitsZ. leptacantha is a diminutive fish, reaching only about 2.5 inches in total length. It’s laterally compressed and has two dorsal fins, the first fairly elongated relative to the second. As mentioned, this species’ color is nothing to write home about (in case you’re one of those types who like to write home about the colors of fish). It’s semi-transparent to yellowish-silver overall with iridescent blue around the eyes as well as blue and yellow accents on the anterior portion of the body. by Saltwater Smarts | May 15, 2016 | Fish, Reef, Science
It’s important to strike a balance between quick intervention and overreaction when it comes to marine fish disease symptomsMost marine aquarium hobbyists keep a close eye on their fish for certain tell-tale signs of ill health. And that’s a good thing, since quick intervention in the case of fish disease can often be the difference between life and death for the specimen(s). On the other hand, we do need to be cautious about overreacting to every suspicious visual or behavioral symptom because sometimes these warning signs may not be what they seem. Remember, if misapplied, medications and therapeutic protocols for fish can do considerably more harm than good. It’s important to have a fairly high degree of confidence in your diagnosis before proceeding with treatment. That means you have to guard against misinterpreting normal behaviors or forgetting that more than one problem can cause similar symptoms.To help illustrate this point, here’s a sampling of symptoms that may or may not spell trouble for your fish depending on the context: Flashing If you’ve ever been through a major outbreak of Cryptocaryon irritans, no doubt the sight of a fish turning on its side and scraping its body on the rockwork causes your heart to skip a beat. And, indeed, flashing is a potentially worrisome symptom. However, this behavior doesn’t automatically signal the presence of a parasite or other problem by Saltwater Smarts | Apr 17, 2016 | Corals, Fish, Invertebrates, Reef, Science
Signal goby (Signigobius biocellatus)The signal goby (Signigobius biocellatus), aka the twin-spot, two-spot, or crab-eye goby, is an appealing little sand sifter with fascinating behavior that, unfortunately, often adapts very poorly to aquarium life. Nonetheless, specimens still appear in the aquarium trade, so it’s worth discussing the species here—if only to understand why it’s probably best to pass it by if you should happen to come across one at your LFS. Physical traitsS. biocellatus has a torpedo-like body shape, high-set, bulbous eyes, a comically frowning mouth, and two prominent dorsal fins. In coloration, it’s grayish overall with orange-brown mottling. Each dorsal fin features a large, distinct eyespot, and the pelvic and anal fins are black with blue dots. The maximum size of this goby is around 4 inches. A crabby mimic When you view this fish in profile as it hovers just above the substrate, the twin eyespots create the impression that you’re looking at a crab scuttling sideways along the ocean floor, which might give would-be predators pause. by Saltwater Smarts | Apr 9, 2016 | Equipment, Fish, Invertebrates, Reef, Science
Smaller fish, such as Blue-Green Chromis (Chromis viridis), are most likely to be affected by chronic elevated dissolved gas levels in your aquariumIf you’re like most marine aquarium hobbyists, you probably don’t give a great deal of thought to the levels of dissolved gases in your system beyond making sure you’re providing good aeration and circulation. But under certain circumstances, these levels can get out of whack to the detriment of marine livestock. Jay Hemdal, Curator of Fishes and Invertebrates for the Toledo Zoo, explains how in the following excerpt from his book The Salt Smart Guide to Preventing, Diagnosing, and Treating Diseases of Marine Fishes.Dissolved gases All aquarists are aware that their aquariums require a minimum concentration of dissolved oxygen in the water for their fish to survive. Many aquarists are also aware that if gases are dissolved in too great an amount, supersaturation can occur, causing serious health problems in their animals. Due to a lack of appropriate test equipment, most home aquarists can do little about measuring for potential problems with dissolved gas levels. There are four basic concerns regarding the level of dissolved gases in aquarium water: acute supersaturation, chronic supersaturation, low dissolved oxygen tension, and high carbon dioxide tension. by Saltwater Smarts | Apr 6, 2016 | Fish, Opinion, Reef, Science
For a zooplanktivore such as Anthias, who are frequent feeders, withholding food isn’t necessarily advantageousQuestionI’ve been told that it’s a good idea to avoid feeding aquarium fish on occasion, for example once every week or once every other week. I guess this stands to reason because fish in nature can’t always get a meal. Do you agree with this, and if so, how frequently do you recommend doing it?” – Submitted by Candace Brown Answer While I don’t have an issue with the practice of occasionally fasting fish, I’m always wary of making any sort of blanket recommendation such as “Marine fish should be fasted every X number of days.” In my opinion, a much better approach is to think in terms of feeding in a manner appropriate to the particular species—which may or may not include fasting. For instance, some predatory species, such as groupers and moray eels, naturally take in large prey items in one sitting and then go without eating for a relatively long interval until another prey item happens along. With these fish, it may be appropriate to feed only once or a few times per week and then allow them to fast in between meals. On the other hand, zooplanktivores and herbivores (such as anthias and many of the tangs/surgeonfishes respectively) naturally feed frequently, if not continuously, throughout the day. Thus, in an aquarium setting, it’s appropriate to provide multiple small feedings each day for zooplanktivores and continuous grazing opportunities for herbivores.
