ellisbart
New Member
Around 4 months ago, one of my Acropora (Acropora gemmifera) that was previously doing incredibly well suddenly lost its shine and spiralled into a decline of health that subsequently led to its death around 2 months ago. The cause, to my shock, was a species of amphipod. I am unsure of the species. However, it is most certainly different from the amphipods regularly observed in the hobby.
Acropora gemmifera (before and after)
They appeared to be nocturnal; hence, all footage was recorded at night with a flashlight. I observed a burrowing behaviour in which the burrow was created directly beneath the lowest point of coral encrustation. Over the course of 4 months or so of observation, it was hard to decipher whether they were inherently Acroporid pests - their behaviour involved repeatedly running over the coral tissue, sometimes following a perfect line before reversing the same path back into the burrow. Corals responded with very limited or no polyp extension, and a thinning of tissue close to the burrow, which continued to expand further up the corals, promoting recession. I did observe what could be the consumption of coral tissue but couldn't confirm bite marks. Therefore, I think the persistent irritation of these pests caused the damage and tissue loss rather than them actively consuming coral tissue. The only time I witnessed what could potentially be coral tissue consumption is videoed above where an amphipod can be seen in the centre of the coral (shortly before the coral completely stn'd). There appeared to be two adults and many transparent juveniles at varying stages of maturity. Oddly, I observed this exact behaviour (two adults and many juveniles) amongst another Acropora colony (Acropora anthocercis) almost immediately after the death of the initially infested Acropora gemmifera.
Acropora anthocercis - (during amphipod infestation) and amphipod comparison
Within the 4 months of dealing with these pests, I tried a few treatments. Initially, I tried filling in the burrow with super glue - they seemingly recreated the burrow in the exact same position (This is also the point where I managed to obtain a specimen for photographing - seen above). I also tried milbemycin oxime treatments that have previously worked for treating ‘white bugs’, reaching a concentration of 18.75mg in 63 US gallons. Surprisingly, this treatment did not work against these amphipods despite killing all other copepod species. (Note - regular or common amphipods also didn’t die).
Upon scrolling Andrew Sandler’s polo reef Facebook forum, I came across a post that pointed me in the direction of a product called debug. The product, formulated and sold by collectors coral’s Anand Kaimal, is a plant based oil blend solution advertised to eliminate all pod species. And so it did. Following Anand's guidance, the parasitic amphipods succumbed to the first treatment a few days after the initial dosage.
Fortunately my Acropora anthocercis survived the amphipods, likely due to the increased surface area that comes with being a small colony, rather than an easily overwhelmed frag like the Acropora gemmifera. The recessed base above the amphipod burrow now has a growth rim for the first time since the amphipods encountered this coral.
I wanted to make this post since I initially felt lost to find nothing of the sort previously documented on any forum I have searched, and since finding a viable solution to the issue, I thought it deserved a post in case it is to help other reefers in the future should they encounter this or a similar issue, and or to identify this species of amphipod - pod specialists welcome!
Happy reefing
Acropora gemmifera (before and after)
They appeared to be nocturnal; hence, all footage was recorded at night with a flashlight. I observed a burrowing behaviour in which the burrow was created directly beneath the lowest point of coral encrustation. Over the course of 4 months or so of observation, it was hard to decipher whether they were inherently Acroporid pests - their behaviour involved repeatedly running over the coral tissue, sometimes following a perfect line before reversing the same path back into the burrow. Corals responded with very limited or no polyp extension, and a thinning of tissue close to the burrow, which continued to expand further up the corals, promoting recession. I did observe what could be the consumption of coral tissue but couldn't confirm bite marks. Therefore, I think the persistent irritation of these pests caused the damage and tissue loss rather than them actively consuming coral tissue. The only time I witnessed what could potentially be coral tissue consumption is videoed above where an amphipod can be seen in the centre of the coral (shortly before the coral completely stn'd). There appeared to be two adults and many transparent juveniles at varying stages of maturity. Oddly, I observed this exact behaviour (two adults and many juveniles) amongst another Acropora colony (Acropora anthocercis) almost immediately after the death of the initially infested Acropora gemmifera.
Acropora anthocercis - (during amphipod infestation) and amphipod comparison
Within the 4 months of dealing with these pests, I tried a few treatments. Initially, I tried filling in the burrow with super glue - they seemingly recreated the burrow in the exact same position (This is also the point where I managed to obtain a specimen for photographing - seen above). I also tried milbemycin oxime treatments that have previously worked for treating ‘white bugs’, reaching a concentration of 18.75mg in 63 US gallons. Surprisingly, this treatment did not work against these amphipods despite killing all other copepod species. (Note - regular or common amphipods also didn’t die).
Upon scrolling Andrew Sandler’s polo reef Facebook forum, I came across a post that pointed me in the direction of a product called debug. The product, formulated and sold by collectors coral’s Anand Kaimal, is a plant based oil blend solution advertised to eliminate all pod species. And so it did. Following Anand's guidance, the parasitic amphipods succumbed to the first treatment a few days after the initial dosage.
Fortunately my Acropora anthocercis survived the amphipods, likely due to the increased surface area that comes with being a small colony, rather than an easily overwhelmed frag like the Acropora gemmifera. The recessed base above the amphipod burrow now has a growth rim for the first time since the amphipods encountered this coral.
I wanted to make this post since I initially felt lost to find nothing of the sort previously documented on any forum I have searched, and since finding a viable solution to the issue, I thought it deserved a post in case it is to help other reefers in the future should they encounter this or a similar issue, and or to identify this species of amphipod - pod specialists welcome!
Happy reefing
