ORA to release captive bred Assessor randalli

by | Dec 14, 2012 | Advanced Aquarist | 0 comments

From ORA:


It is rare to find an entire genera of reef fishes extremely well-suited to live in an aquarium, but Devilfish (Assessor spp.) make great aquarium residents for several reasons.  Their maximum length of 3 to 4” makes them suitable for most sizes of aquariums.  They aren’t overly aggressive with other species or conspecifics and can be kept singly or in groups.  Assessors frequently exhibit a unique and rather humorous upside-down swimming behavior.  Finally they are easy to keep since they easily adapt to various commercial and prepared diets.

Here at ORA we have been raising Yellow Assessors (Assessor flavissimus) and Blue Assessors (A. macneilli) for nearly a decade.  With the help of our friend Koji Wada at Blue Harbor in Japan we recently acquired a new species to the US  trade, A. randalli.

At first glance, a Randall’s assessor could be confused with a Blue Assessor, however Randall’s assessors are more likely to exhibit upside-down swimming behavior and their color scheme is more elaborate.  The majority of their body is blue with the interior of each scale containing a rusty red dot.  The head region is green-blue and their fins contain rays of green, red and orange. These subtle colors are best observed when keeping a small group of them in a reef tank with other boisterous but unaggressive species.

We recently had our first small batch of Randall’s assessors go through metamorphosis and now we are working on building up numbers of this unique fish.  Fortunately Randalls assessors are nest spawners, similar to Yellow Assessors rather than mouth brooders like the Blue Assessor.  This leads to large nest sizes and we expect this will lead to steady availability with the first fish reaching the market in early 2013.  We are excited to share some short video clips of some of our eldest F1 individuals.  They begin to look and act like miniature assessors shortly after metamorphosis.

Thanks to Kevin Kohen for letting us use his Randall’s Assessor photo.

  • Leonard Ho

    I'm a passionate aquarist of over 30 years, a coral reef lover, and the blog editor for Advanced Aquarist. While aquarium gadgets interest me, it's really livestock (especially fish), artistry of aquariums, and "method behind the madness" processes that captivate my attention.

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