Draft* Breeding Protocols for a Nassarius sp. Snail
(Tentative ID: Nassarius Pauper)
Overview:
The Reef Stewardship Foundation (RSF) has tentatively identified a species of Nassarius rarely seen in the marine aquarium hobby in the USA that appears to breed easily in most aquariums given appropriate care and conditions. No previous records of this species being bred in aquaria, or outside of, the USA has been found, if you are aware of an earlier report, please contact the RSF at info (AT) reefstewardshipfoundation.org. This document attempts to establish a standard set of protocols associated with the tasks of breeding this species.
Tentative Identification:
This species has been tentatively identified (though not officially confirmed at this time) as Nassarius pauper (sometimes referred to as Nassarius pauperus) from the western Pacific Ocean. However, since the origin in the wild of this species is not known, this is only a tentative ID.
Nassarius pauperus information page on Gastropods.com:
http://www.gastropods.com/0/Shell_5660.shtml
Origin:
The RSF Nassarius originated from a Colorado aquarist Terri (screen name Zerrilit) and was distributed by Brian Plankis prior to Project DIBS merging with the RSF. Terri first saw the species in her aquarium after a shipment of Fiji live rock and sand was placed in the tank. So it is possible the species originated in Fiji, but cannot be confirmed.
After obtaining 8 specimens of the species I have successfully continued to breed them and am now re distributing them throughout the USA. Much (if not all) of the information detailed herein can be found at the Reef Stewardship Foundation forum dedicated to the species:
http://www.reefstewardshipfoundation.org/forums/forumdisplay.php?f=133
General Species information:
Size:
Ranging from < 1mm to 3/4 inch shell length. Minimal reproductive size and how much time is needed to reach sexual maturity is unknown at this time, but suspected to be around 1/2" in shell length and 90-160 days respectively (Possible research project)
Reproduction:
Adults lay round egg cases on flat or nearly flat surfaces with glass being a common surface. Reproductive cycle is not fully known at this time but larvae are pelagic (Shimek, Plankis) or substrate dwelling and non planktonic and not free swimming veligers. This factor alone is most likely the leading reason for success in captive breeding. Larval stages at this point are unknown and research is needed in this area.
For pictures and video of the egg cases laid by this species visit this thread:
http://www.reefstewardshipfoundation.org/forums/showthread.php?t=1719&page=3
Diet:
Carrion and detritus feeders, will survive on detritus and leftover fish food within the sand bed when not directly fed. Thrive when directly fed meaty foods such as pellet or fish mush.
Suggested Breeding System:
For breeding purposes, a stabilized saltwater or reef type system with water quality kept well within reef tank parameters will suffice.
The ideal environment provides at least 1 inch of fine sand bed with some larger particles mixed in as to avoid compaction. Salinity should be kept between 34 and 37 ppt. with temperature between 77* and 82* F. The effects of photoperiod on breeding are not known at this time (Possible research project), but the snails are not photosynthetic, so normal output lighting will suffice and may help the snails locate food. It may be possible to raise the snails without lighting, but this would need to be researched. May be co-cultured with other species so long as tank mates are not extremely predatorial towards larvae and/or culture tank provides ample room to hide. Maintenance of calcium and alkalinity is required as the snails utilize calcium to build their shells.
Ammonia levels should be kept at or near 0ppt (as well as can be measured) with Nitrites and Nitrates also being at or near 0ppt. Nitrates may climb as high as 40ppt with no observed ill effect however this environment is not ideal and should not be maintained for long if at all.
Calcium should be maintained between 370 and 540 ppm and Alkalinity levels should be kept between 8 and 12 dKH. While not confirmed through testing, it is likely that the best growth results will be achieved at the higher end of these ranges (Possible research project).
Substrate should consist of fine aragonite sand, with some larger particulates such as crushed coral or some rock rubble mixed in to avoid sand compaction. Thickness of 1” or deeper is preferred however thicknesses deeper than 2” may not provide any additional benefits. Substrate should be stirred gently every 30 days to release excess detritus and reduce compaction rate. While not preferred, live rock may be placed in the system. However, it must be noted that larger substrate surface allows for a larger area for the specimens to live in and adding live rock reduces the availability of their preferred habitat and also could lead to introduction of predators of the adults or larvae.
Ideal stocking levels for this species are not known (Possible research project), but a good rule of thumb is to keep no more than 20-30 adults per 10 gallon tank to maintain a successful breeding population. Excess adults should be moved to other holding / propagation systems to maintain generation rates and health. Density may be increased in systems with deeper sand beds (deeper than 1”) or heavier feeding.
Filtration for propagation system is best achieved through plumbing system in a flow through design to an existing reef or filtered system however other methods can be achieved. A simplified system can be maintained using a single sump with live rock and live rock rubble so long as the sump maintains at least a ½” sand bed for specimens that make it through the overflows. Sump should be checked regularly for such specimens.
Depending on individual preference, the use of macro algaes, skimmers, and other methods of filtration (canister filter, etc.) may be run. Any mechanical pumps should have screens to reduce possibility of larva and adult specimens getting caught in impeller systems.
Food Sources:
Best results have been achieved utilizing meaty food sources with low buoyancy, common pelletized fish foods such as Formula One are ideal. Pellet size should be as small as possible to aid in ease of consumption. More work is being put into the preferred amounts however it has been noted that productivity rates are much higher when the system is fed a large amount over time (small amounts more frequently), food should be added at least twice every 24 hours.
With regard to water quality, excess leftover foods that do not settle into the sand bed should be removed promptly. Maintaining this system with so much food at first will appear to be an uphill battle however over time sufficient scavenger feeders will appear and assist in cleanup (Polychaetes, Gammarid Amphipods, etc.) The system should be examined to ensure that scavengers do not outcompete the snails for food.
Water Quality Maintenance:
As stated above, water quality becomes of high concern in relation to the amount of food injected into the system. The use of protein skimmers to remove excess organic compounds and macro algaes to uptake Nitrogen is a near necessity. Water changes are a base requirement and should be done on a regular basis with 10% weekly showing to be a good baseline. Aside from providing a means of nutrient export these water changes also help to maintain required trace minerals and calcium / alkalinity levels in the system.
The sand bed should be stirred gently at least once a month to release settled detritus into the water column where it can be removed through regular methods such as water changes or mechanical filtration. Should water changes fail to maintain calcium and alkalinity levels addition of supplements will be needed, this can be in the form of a 2 part solution, B-Ionic, other supplement, or through the use of a reactor.
