Grumpy Old Reefer » Invertebrates

Coralscience.org is building a mesophotic reef system

Grumpy Old Reefer — Wed, 03 Feb 2010 10:00:07 +0000

Tim Wijgerde et al. are starting a very interesting project at Coralscience.org: they are building a low light reef tank (modelling “mesophotic” reef system) using equipment and foods available to all aquarists. I’m sure we “hobbyists” can learn and benefit from this work by marine scientists.

Read all about it here.

Special Diseases of Aquatic Organisms journal issue: The Role of Environment and Microorganisms in Diseases of Corals

Grumpy Old Reefer — Wed, 18 Nov 2009 06:07:30 +0000

A special issue of Diseases of Aquatic Organisms titled “The Role of Environment and Microorganisms in Diseases of Corals” has been published online. And the best part is that all articles are Open Access!

From the title page:

“This DAO Special contains papers based on presentations made at the 11th International Coral Reef Symposium (2008, Fort Lauderdale, Florida, USA). The contributing authors provide an update on coral disease research, including new advances in the microbiology of causative agents, epidemiological modelling studies, and the role of climate as a driver of disease. They also consider management needs in light of a rapidly changing environment of coral diseases.”

Latest additions

Grumpy Old Reefer — Wed, 30 Sep 2009 16:14:58 +0000

Last week I received an animal shipment from Mrutzek Meeresaquaristik. Once again, Mrutzek Meeresaquaristik provided excellent service, something that is unfortunately not common in EU online shops.

All animals were in good condition although the Colopometra sp. crinoid was understandably damaged during the shipment. I’m happy to report that it is already recovering fast, I can see new growth daily.

One more thing about Mrutzek Meeresaquaristik: it seems like this is the only place you can get full range of invertebrates for reef aquariums. All the rest offer the same old Acanthastrea, Acropora, Montipora etc. Some don’t even have anything other than stony corals. As sad it is, Mrutzek Meeresaquaristik seems to be alone in its class and really the only option for serious aquarist.

In addition to animals pictured below I also received 6 Berghia verrucicornis, 5 Pseudanthias squamipinnis and 3 Pseudanthias dispar.

[Show as slideshow]

Tank update, July 2009

Spongeguide.org

Grumpy Old Reefer — Wed, 17 Jun 2009 07:08:15 +0000

Sponges are one of the more beneficial invertebrates for reef aquariums due to their great ability to filter DOM and bacteria out of the water. Plus they are colorful, have interesting shapes and many have modest husbandry requirements if properly fed.

A new guide for Caribbean sponges is available at spongeguide.org. They have more than 170 sponge species in their database.

“Your photographic guide to over 170 species of sponges found on Caribbean coral reefs and associated rocky and lagoon environments.”

Coralscience.org is building a mesophotic reef system

Fantastic example how complicated our aquariums can be

Grumpy Old Reefer — Fri, 27 Mar 2009 22:02:31 +0000

I just found this paper while searching for something completely different but what a gem it was!

Selden et al. Waterborne cues from crabs induce thicker skeletons, smaller gonads and size-specific changes in growth rate in sea urchins. Marine biology (2009) vol. 156 (5) pp. 1057-1071

Indirect predator-induced effects on growth, morphology and reproduction have been extensively studied in marine invertebrates but usually without consideration of size-speciﬁc effects and not at all in post-metamorphic echinoids. Urchins are an unusually good system, in which, to study size effects because individuals of various ages within one species span four orders of magnitude in weight while retaining a nearly isometric morphology. We tracked growth of urchins, Strongylocentrotus droebachiensis (0.013–161.385 g), in the presence or absence of waterborne cues from predatory Jonah crabs, Cancer borealis. We ran experiments at ambient temperatures, once for 4 weeks during summer and again, with a second set of urchins, for 22 weeks over winter. We used a scaled, cube-root transformation of weight for measuring size more precisely and for equalizing variance across sizes. Growth rate of the smallest urchins (summer: <17 mm diameter; winter: <7 mm diameter) decreased by 40–42% in response to crab cues. In contrast, growth rate of larger urchins was unaffected in the summer and increased in response to crab scent by 7% in the winter. At the end of the 22-week experiment, additional gonadal and skeletal vari- ables were measured. Cue-exposed urchins developed heavier, thicker skeletons and smaller gonads, but no differences in spine length or jaw size. The differences depended on urchin size, suggesting that there are size-speciﬁc shifts in gonadal and somatic investment in urchins.

Full paper available here

What this study (or rather, the mini review in Introduction) explains is that various invertebrates react to chemical cues from their natural predators in a quite dramatic ways. Their shells can become thicker, they might alter growth rate and reproduction, their behavior might change to more cryptic etc.

If we think how small the water volume is in relation to the biomass in our aquariums it’s no wonder that we have individuals behaving differently in different aquariums with all the chemical cues flowing around. For example, I have had this long lasting “problem” with Lysmata spp. cleaning shrimps constantly hiding inside the structure while the exact same species in other tanks are very courageous. The answer to this mystery might very well be that I have some predatory crab or fish in my tank that the shrimp can sense.

This paper also highlights the point that one can not give blanket statements on invertebrate husbandry because there are just too many variables. The only way to be really successful is to study the biology and ecology of the animals you are interested in and their natural environment.