Many species of grouper can grow really large and exceed 100 cm (over 3 feet) in length. The species Epimetheus lanceolatus (Bumblebee grouper) is known to grow especially larger and there are many unverified reports of huge specimens form South-East Asia.
A grouper will typically have a stout body with a larger mouth and it is not a very fast long-distance swimmer. The edges of the jaw are fairly toothless, but the grouper is equipped with tooth plates inside its throats that are used to crush prey.
They fish fills its large mouth with sand and jets it out through the gills and this makes the grouper a highly efficient digger. When a grouper feels threatened, it will seek shelter in its dug out cave and extend its gills.
Groupers are protogynous hermaphrodite, i.e. a majority of the young specimens are female but will turn into males as their size increases. Beautiful, charismatic, and robust, the groupers of the family Serranidae offer much to those with enough space to accommodate their basic needs.
This is a diverse group of fish that includes aquarium favorites such as antics, bassets, and hamlets. Here I want to focus on the subfamily Epinephrine, specifically on the smaller, aquarium-suitable representatives that are easily obtainable in the hobby.
The subfamily includes some true monsters that are best left in the ocean, but there are also plenty of species that can be housed in a 200-gallon-plus aquarium, and some are even small enough to make do with slightly smaller accommodations. As with all common names, this is purely arbitrary, and the hinds were at one time groupers in good standing.
I’ll lump the hinds and groupers together here, as their care, general morphology, and behavior are more or less identical. Ranging in color from drab to stunningly vibrant, even the less-garish species possess a personality that endears them to many keepers, including yours truly.
Often when peering at a grouper in a large marine aquarium, you’ll find it actually looking back at you, as if wondering just exactly what you’re up to! It’s very important that the aquarium is realistic when considering buying one of these specimens at his or her local fish store.
Though they are stunning animals, they are often victims of classic impulse purchases by aquariums with accommodations that are far too small. This is both to provide the needed swimming space and to make sure dissolved nutrients are kept at reasonable levels between water changes.
While small individuals are often offered for sale, they can grow quickly, and you shouldn’t get one thinking you can get a bigger tank down the road. As mentioned above, 200 gallons is a good minimum target if one is planning on keeping a grouper with a handful of other appropriate fish, but a few of the smaller species such as C. Formosa or E. Angus can live quite comfortably in a 120-gallon or larger community aquarium, whereas larger species such as the lyre tail grouper Various lout, the spotted coral grouper Plectropomus maculate, and the tomato hind Cephalopods sonnet all need accommodations of greater than 300 gallons.
The aquarium should steer clear of narrow show tanks and look for aquariums with a front-to-back measurement of at least 24 inches for most species. Additionally, out of sight is out of mind with regard to territorial disputes, and plenty of rocks will mitigate aggressive interactions with tank mates.
A small 3-inch coral hind or miniature grouper C. minima is easy to accommodate in a 40-gallon tank, but shortly down the road you’ll have a fish on your hands that has outgrown its quarters and then some. As it grows, however, it places an increasingly large load on the filtration system, and managing the nitrogen cycle can become a real challenge.
An 11-inch honeycomb grouper E. hexagonal puts away a considerable amount of food, with a waste output to match! At a single feeding, a fish this size can easily eat two 8-inch squids whole, and a proportional amount of waste is produced as a result.
Groupers are resilient fish and thankfully handle shipping well, so most specimens are still in fine shape by the time they reach your local store. When introducing a grouper into your display (after a six-week quarantine period, of course), it’s a good idea, if practical, to rearrange the decor in order to break up existing territories in the tank.
This way the fish in question are again on equal footing, neither has an established territory, and both are somewhat disoriented at suddenly finding themselves in new surroundings. The established fish will invariably be irritated at the new arrival in his territory, and will hold the upper hand in the inevitable confrontation.
This displaying, gaping, chasing, and ritualized combat starts out rather intensely by both individuals, and decreases in frequency and severity over a matter of hours. While this might seem a straightforward consideration, these fish can surprise you in this regard, so err on the side of caution when picking tank mates.
When selecting tank mates, keep the likely adult size in mind for all species that you’re considering, as well as the growth rates of all fish concerned. An often-overlooked aspect by lazy keepers, variety in the diet is essential, and every effort should be made on the part of the aquarium to make sure the fish in his care receive a varied array of food offerings.
It should be noted, however, that all predators, be they reptiles, birds, cats, or fish, need whole food items in order to obtain all the nutrients they require, not just meat. Additionally, there are frozen preparations available that are already vitamin fortified, which make excellent food for these fish.
Grouper is at the center of all group and access policy management. Managing access with Grouper results in access to target systems being automatically kept in sync with policy as subject attributes change in underlying systems of record (e.g. ERP, SIS, etc).
This overall mechanism coupled with powerful distributed management capabilities is what makes Grouper a core component of the Uncommon Trusted Access Platform. The Grouper project maintains three introductory videos that are a bit dated, but still very relevant.
The third and final in the series, Intro to Grouper : Grouper Toolkit Components, describes the various product components and capabilities, and options for integrating with existing campus IAM architecture. The University of Chicago VPN example described in the Intro to Grouper series, provides a great overview of how a variety of Grouper ’s capabilities come together to implement powerful access control management, and illustrates a common pattern that can be applied in many situations.
These are groups of subjects that share some characteristics, such as being a student, a postdoc, or a member of the IRB office. The IRB office reference group is kept up to date by directly adding or removing members via the Grouper UI.
Reference groups are institutional meaningful concepts and represent the best known “truth” about a subject at any given moment. Grouper provides a single point of management, enables groups to be defined once and reused across multiple applications, and empowers the right people to manage access.
Grouper is organized around three main concepts; folders, groups, and memberships. Intersection includes entities that belong to both of the original factor groups, and produces a composite “members-in-common”.
Complement includes subjects that belong to the primary “left” factor group who are not also members of the secondary “right” factor group (i.e. “left” minus “right”). A rule can detect actions, check conditions, and do resulting operations.
Each folder, group, and attribute has its own privilege assignments which enables fine-grained access control and delegation of authority. The Access Privileges definition in the Grouper glossary provides further details on what.