#brackish fish

[fishcommunity]

I'm glad my brackish tank is coming together again. This used to be my brackish community tank, but after my Knight Goby died I admit I paid less attention to it. After catching a Rainwater Killifish locally earlier in the Summer, I picked up some of our local ditch shrimps and tried a native brackish biotope. With no more Rainwater catches after 5 more trips, and the brackish algae dying back for the season, again I was dismayed.

Now after some hornwort addition, some new lighting, and some duckweed growing, it's starting to feel on its way to a real tank again. It's a good feeling.

[aquariuminfobureau]

How to care for the spotted scat

One of the iconic fishes for the brackish aquarium, is the spotted or common scat, Scatophagus argus. It is sometimes called a butterfish, although unrelated fishes share that name. The so-called red scat is sometimes traded as a seperate species or race of S. argus, however it is demonstrated to be a naturally ocurring color morph of the spotted scat. Most spotted scats belong to the more typical morph, which is traded as the green scat, or just the scat. This is because the other species appear too rarely in the aquarium trade to have become familiar to aquarists.

The typical length for a mature S. argus, both in the wild and in the aquarium, is 15 to 20 centimeters or 6 to 8 inches. A scat that is 30 centimeters or 12 inches long is considered large, and the recorded length is 38 centimeters, or about 15 inches. This is a venomous fish with a catholic diet, distributed in the Indo-West Pacific region, in a swathe from the Persian Gulf to Japan and Australia. The primary habitat of S. argus is mangrove estuaries, where it associates with mangrove flora.

Mature fish are also found in shallow, inshore marine environments, where they associate with seagrass, rather than reef-building corals. Wether in fresh or brackish water, they are found in areas of muddy substrate. These fish may be numerous in areas of reduced salinity, but records from non-estuarine stretches of rivers are rare. They do frequent upstream stretches of streams, but they remain close to the estuary. Although S. argus can survive in good health when it is maintained in freshwater, I do not consider them a freshwater fish, at any stage in their life cycle.

There are in fact a few related species all called scats, belonging to the extant sister genera Scatophagus and Selenotoca, and the fossil record of the scat clade extends back to the Eocene epoch. Zoologically the scats are part of the acanthuriform nexus of fishes, which is mostly marine, and includes the tangs, butterlyfishes and angelfishes of the reef, among others. Among this group the scats have a reputation as unusually euryhaline, capable of frequenting both fresh and salt waters. Addituonally S. argus also been noted to have broad tolerance of temperature and pH.

Much confusion exists among aquarists, surrounding the salinity needs and optimums of S. argus. Despite their hardiness, unfortunate S. argus suffer and die in home aquariums, or skulk alone in a store. Often aquarists are daunted from purchasing a scat, by misinformation about their needs. Thai aquaculturists report that the culture of S. argus requires a specific gravity, of at least 1.002, or a 'low end brackish' setting. Although scats can be acclimatised to life in true freshwater, it is not their natural habitus.

In a study of wild scats in a mangove environment, the older scats lived where the specific gravity was around 1.02. Juvenile scats were found upstream of them, where tidal influence on salinity was less, and the spe ific gravity was 1.02. Elsewhere it was found that the embryonic development within scat eggs, was optimised when the specific gravity is 1.01. Although some sources insist that scats may only be accommodated in freshwater, if the water parameters are hard and alkaline, collection data shows wild scats are present where the pH may be as low as about 7. It is true that scats are not found where the water has the soft, acidic parameters favoured by so many popular freshwater species.

The genus name Scatophagus, which is obviously abbreviated to the vernacular 'scat', means an eater of faeces. This alleged feeding habit, which causes much amusement, actually remains unproven, although scats have adapted to the human presence on the coast, by frequenting harbours and wharfs. There people dump their latrine and other waste into the water, in the area where fishes such as scats were feeding. Although they might not seek faeces to eat, I feel sure that they obtain some benefit from byproducts of human presence, as do rats and mice, pigeons, seagulls, and the like above water.

Juvenile scats, particularly, are known to consume organic detritus, and mud is intentionally ingested by this species, because it is recovered among their other gut contents. That these scats scavenge opportunistically is the most likely explanation for the presence of fish scales in their gut contents. Because scats are unlikely to nip scales from live fishes swimming by, the most likely source of the ingested scales was nibbling at fish carrion when they encountered it.

S. argus has a very broad dietary range, and the composition of its diet changes with growth. Juvenile scats consume more plankton, but as they grow, they switch to intensify their grazing behaviors, and for this reaon their mouths become subterminal in position. Their diets include a variety of items, from fish eggs, to arthropods, to sessile fauna, and both micro- and macroalgae. Although they are thus most often classed as omnivorous fishes, S. argus has the expanded gut of a herbivorous fish, and the form and function of its teeth and face are optimised for grazing activities.

Depite their strongly herbivorous leanings, a part of the natural S. argus diet includes animals such as sponges, bryozoans, hydroids, and tunicates. One source reports the inclusion of coral and anemone polyps in their wild diet. Unfortunately, the size and systematics of the polyps consumed, was not reported in the paper. Although some saltwater aquarists have maintained older S. argus in reef tanks, where they graze on algae and sessile organisms found on 'live rock', they sometimes nip at delicate, sessile ornamentals such as the popular feather duster worms.

Feeding S. argus in the aquarium is not at all difficult, although the diet provided for them, must be rich in algal or other vegetable material, of the sort offered to herbivorous fishes. Their aquarium environment should be a mangrove biotope, with a soft substrate and wood as decoration. Alternatively the mature S. argus are well suited to a true saltwater lagoon biotope. Such a tank has marine water parameters, a soft substrate, and some calcareous rockwork in the aquascape.

S. argus are regarded as semi-aggressive yet gregarious with their own kind, faring best when housed in a group of conspecifics. Each fish will need not only swimming space, but also a number of retreats from one another. Unfortunately S. argus, being a herbivorous fish, is not unlikely to attack ornamental plants, once it has matured into a more herbivorous growth stage. This means that live plants, including marine macoalgae, will be nibbled or outright devoured, unless they are unpalatable to S. argus.

Juvenile S. argus will require a 'low end brackish' specific gravity, but older fishes occur in 'mid range brackish' to marine environments. Although comparatively few aquarium fishes are inhabitants of brackish waters, there are a variety of peaceful species that are suitable for sharing such a brackish, mangrove biotope. When transferring scats, or any other euryhaline organisms between two aquariums, they must be slowly acclimatised between the two different levels of salinity. This is so that physiological changes can take place, and to prevent osmotic shock.

In their native range, S. argus are found where the water temperature may be as low as 20 degrees centigrade in some months, but up to 29 degrees during other parts of the year. They begin to experience thermal stress, ony at something like 33 degrees, and they can temporarily tolerate such temperatures, but not higher temperatures of around 40 degrees. Like many fish and crabs from mangrove environments, S. argus is well used to thriving at temperatures that are a little higher than those in the average tropical aquarium, which is usually 24 or 25 degrees. Yet S. argus also fares fine at such an ordinary tropical tank temperature.

[captainofsalt]

Captain update: Currently writing a research doc for my dad, who's setting up a brackish aquarium and needed water parameters and tank cycling info. He's getting back into fish keeping and is still a Beginner, but couldn't find any books on Euryhaline fish keeping within aquariums and wanted me to do research for him, which is my specialty! It is 6 pages long so far. It focuses on brackish aquariums and cichlid and community tanks under 40 gallons.

If anyone is interested in having Access to it once it's finished, let me know and I'll update this post with a link! I'm not an expert by far but I've accumulated research from many different sources and will include those sources in the final document !!

If anyone has any recommendations for good sources of info, do let me know as well! It is Difficult to find anything since brackish aquariums are not often marketed to people on a large scale in comparison to freshwater and marine aquariums.

It won't be finished for a while yet, since I plan on waiting until the aquarium is finished so I can add my own experiences and observations to it.

[have-you-seen-this-animal]

The second image is of a different species, the largescale four-eyes (Anableps anableps). I included it due to how well it shows the eye, and as a result of far fewer photos available of Anableps dowei. This animal was requested!

[likesplatterpaint]

Bonk is just so Shaped.

[fishyfishyfishtimes]

I drew Ahti II's pet pike!! Her name is Kultakutri (Goldilocks) and she's a Golden Royal domestic pike, a breed that has been specifically bred to appear as light and yellow as possible.

Ahti II raised her from an egg and she’s about ten years old now — doesn’t mean she’s not Baby anymore, though.

[prisiidon]

@kenneduck does ur freshwater domain stock algae-based skin care products- Byers is interested- actually both Lio and Byers wanna eat algaE. allies bc of food dghfdsfhg

[sadboygrim]

Blue 🦀

[aquariuminfobureau]

The genus Brachygobius is a nexus of species in the true goby clade, that are collectively known as bumblebee fishes or bumblebee gobies, in account of their colours and patterning. Often they are seen in dealers aquariums, because they are petite and beautifully colored. Yet much confusion exists as to which exact species is being traded, and what water conditions they might benefit most from, or are natural to the wild gobies. Particularly, the question of proper salinity, with confusion and dubious, repeated 'facts' as to their wild habitats.

B. doriae, B. nunus, and B. xanthozonus in particular, are often confused, and indeed, there is confusion even among ichthyologists, as to which of the Brachygobius species an individual bumblebee fish, or Its population, might belong to. The species of Brachygobius are, in nature, partially separated by environmental niche partitioning, with some species present in wild freshwaters. However, the Brachygobius sp. most usually encountered in the aquarium trade, are in fact from brackish waters.

For instance, B. doriae is sympathetic with Rhizophora mangroves, as well as fish like mudskippers, siganids, and archerfishes, in the muddy lower (and thus tidal) reaches of tropical Asian rivers. Thus this species, chosen as an example, would appreciate a quite higher brackish salinity, than books might suggest. But also, it's presence overlaps with that of the palm, Nypa, which is not as salt tolerant as is Rhizophora, so it would be wrong to reckon B. course as a marine fish.

Smaller Brachygobius species, such as B nunus, might grow to around 1 inch or 2.5 centimetres long. Larger congeneric species of bumblebee fishes, can grow to about 4 centimeters, or over 1 and a 1/2 inches. The small size of these beauties has often appealed to those seeking oddballs or brackish fishes, but finding themself with limited space. Although the male gobies can be territorial to one another, its possible and imperative to house members of these species, in a group of about six or more fishes. Single fishes are too easily stressed, it seems. A combination of factors makes these fish unsuitable for a typical community tank, although with careful thought, they can share with other benign brackish fishes.

Its also worth noting that these gobies appreciate it demand warm end tropical temperatures, higher than the 24 degrees centigrade standard, that is probably the norm for tropical tanks. Perhaps a temperature between 25 and 28 degrees centigrade would be ideal for their aquarium. The wild gobies show a positive association, with a muddy substrate. Again contrary to information in books, these gobies do not need crystal clear water, as they evolved in conditions of turbidity. Their presence in mangrove habitat, means that non-toxic leaf litter and wood, are suitable choices for the aquascape also. Wood could be arranged to imitate the appearance of mangrove roots.

Brachygobius sp. aren't quite as finnicky about eating, as some aquarium literature might lead you to believe. These gobies will, at least if acclimatised, take to defrosted foods, and do not require regular feedings, of love invertebrate prey. Some of them even adjust to nipping proprietary flake foods, although it must be cautioned, most of them will not accept manufactured substitute diets. Given that misinformation about feeding this genus, has daunted many aquarists from attempting bumblebee fishes in the aquarium, it isn't really a basis for most fishkeepers to fret unduly about. Misunderstood fishes that are not eating, are presumably stressed in some way.

[mumblelard]

i found a hatchet half-buried in the muddy wetlands. i rinsed him off in some stormwater and carried him the rest of the way home. i realize now that i should have just let him be, but that didn't occur to me until it was too late. now, i suppose, we wait

addited: finnie agrees that nothing good can come of this

[anabantoid]

Funny Scorpaeniforme.

[thebaltimoreyoudontknow]

I remember when they started educating us about oysters and their importance to the bay! They would set up booths at festivals in Baltimore with aquariums full of oysters. It was very cool - I don't remember the year they started but 2014 seems about right.

Maryland has been working with other states on conservation efforts. We have made steps towards protecting the Chesapeake Bay, which is the largest estuary in the United States. The hard work seems to be paying off!

[eiscuseme]

theres different eiscue for diff water salinity??

There ARE !! theyre all the same species, obvs, and not nearly different enough to be categorized as different species. But generally, brackish eiscue can withstand warmer weather a lot better and can freeze faster when the weather changes. Saltwater and freshwater eiscue prefer it colder, with saltwater eiscue being uncomfortable in hot weather (hence their migrations to the poles!) Freshwater eiscue are the easiest to care for tho and most captive bred eiscue are of the freshwater variety (slushee is a freshwater eiscue!)

Its super cool their ice even has different looks! You can kinda see through the ice of brackish eiscue :D

[supercantaloupe]

if you were a fish, which body of water would you live in?

estuary :) best of both worlds babey (salt + fresh water)

[doctorwormcore]

i love my pandas so much! They aren't shy and seem to love exploring the tank! They're really interested in my snails tho 👀👀👀