Horn sharks
I wanted to know what can a horn shark live with in an aquarium.
<Other cool/coldwater organisms that it can't or won't eat... Please take a read through www.WetWebMedia.com using the search term "Horn Shark", and get your hands on Scott Michael's recently redone shark book... will save you a good deal of money and grief. Bob Fenner>

Not Using WWM, Mixing a Coldwater Shark With Incompatible Tropicals
Hey, I purchased a Port Jackson shark a few days ago and I was told to lower the temp what temp should it be at? I also have some angels and triggers in the tank with the port Jackson. What is a safe temp for all the species. I do have a chiller. Thank you.
Derrick
<... these fishes and their environments are incompatible... Please read here: http://www.wetwebmedia.com/portjacksons.htm and the Related files linked above, and separate these animals. Bob Fenner>

Smooth Hound Zebra Eel combo 11/3/05
Hi, I have just a quick question. I have read pages and pages of Zebra Eel, and Smooth Hound Shark articles on various web sites but mostly on WWM. I have acquired a great deal of knowledge on both species, but my question is can they coexist in the same aquarium peacefully. I have a 400 gallon aquarium with 2 Grey Smooth Hounds, a Porcupine Puffer, and a Remora. My father is getting out of the hobby and has given me his 2 1/2 foot Zebra. Could this be a peaceful combination?
<Could... or not. Hard to feed the Eel in the presence of the sharks, puffer...>
With them both having poor eyesight and eating similar foods. I want to also mention the sharks are 1 male and 1 female
still babies at about 20 inches, and the tank is a temp tank and will be moving to larger in a couple years as they all grow.
Thanks for your time,
Brandon
<Mmm, worth experimenting... with intermediate temperature to accommodate all... Not likely to be much inter-species aggression here, but only first-hand experience can/will tell. Cheers, Bob Fenner> 

Sharks
<Pam, Lorenzo Gonzalez, responding for Bob-in-Indonesia>
Hello,
I got a question about adding a new fish to my tank My tank is 125 gallons I have about 150 pounds of live rock 2 in. deep sand bed for filtration I have a emperor 400 and a Skilter 400 also 2 maxi jet 1200 power heads for circulation. 
<That's grossly under-filtered. oh. well, maybe not for just one small puffer.>
The only fish in the tank now is a stars and stripes puffer I would like to add an epaulette shark about 12 inches and my puffer is about five will this work out okay with just these 2 fish I might maybe add 1 more down the road a little ways but not for a while and definitely before I get the shark I will get a big protein skimmer besides the Skilter and about another 100 pounds of live rock. 
<If you're quite set on a shark, (how 'bout a trigger, grouper or lionfish instead?) - I'd forgo all the extra live rock in favor of a much, MUCH more powerful filtration system, maybe a big Eheim canister, one of the wet/dry models, as well as a powerful skimmer. A leopard (you mention one below) will need mucho 'cruising space'.>
If this will not work can you tell me what else I need to get for my tank? 1 more question the epaulette shark is 260 dollars is that to much
<Too much for me - but sounds pretty typical.>
but it has been there for 4 months and is eating great also if I should not get the epaulette would I be able to get a real small leopard because the LFS also has 1 of them but it is smaller than my puffer so I don't know if that would be good. 
<With all that rock, the leopard would probably be able to stay out of the puffer's way. But less than 5 inches is awfully small to be buying. And keep in mind that both of these sharks will WAY outgrow your 125 gallon tank in a year or two - the 12-inch epaulette even sooner. 
-Regards, Lorenzo>

Horn shark
I am looking for some info on the care and species info on the horn shark, Are they compatible with small marine fish? What do they eat? How much room do they need? How big do they get ? etc... Your help would be greatly appreciated.
Thanks, Jeff
<There are a few species of Horn Sharks, family Heterodontidae, offered from time to time in the trade... the cooler water Californian, Heterodontus francisci, and the more tropical, H. portusjacksoni mainly... though the pretty H. zebra is occasionally seen... and there are five more species in the genus...
They eat invertebrates found on the bottom and small fishes... all get to about four feet long. Need aquariums in the hundreds to thousands of gallons size. Not compatible with small marine fishes... will eat them if hungry, or the opportunity arises.
Bob Fenner>

TANKMATES FOR SHARKS
Well Anthony thank you for your opinion, you're not the first to be surprised about my accommodations. My shark frenzy started with 2 leopard sharks towards the end of last year & I readily bought them because I was planning on upgrading to a bigger tank within a month or so & they were soon going out of season. After the first, buying the others was irresistible & I figured since 3 of my 5 sharks were slow or non-moving, they would all be alright in a 125 gal. tank. They all look healthy & tolerant of each other, with the exception of tolerant in the case of the leopards. The fault is all mine & I am willing to give up my sharks when their too large- but for now its shark mania, thanks!!
<Hello. This is Steven Pro "speaking" now. Sorry to butt in but it appears Anthony did not get across the desired meaning. He was not surprised as much as he was appalled and I am too. Your new larger tank is inappropriate even for one of the smallest sharks you have. You admitted you were willing to give up your sharks when they grew too large. Well, now is the time. They are already too large for you and your tank. Please do the hobby a service and find appropriate accommodations for your animals. Sincerely, Steven Pro>

Trade in of a cool water shark for a tropical
Hello Bob,
Thanks for all the quick replies you have sent me I have the 125 with the leopard shark, stars and stripes puffer, and honeycomb grouper since you say the shark will probably not last long in my tank I was thinking trading him for a marbled cat shark or epaulette would one of these be a better choice but my leopard shark is still doing great he eats just
about anything I put in the tank but I don't really want to risk it dying
<I agree with your point of view>
I just added 2 CPR Bak Pak protein skimmers and added 2 more MaxiJet 1200s all my water perimeters are good ph-8.2-8.3 ammonia and nitrite are at 0 and nitrates are at 25 so I was wondering after I trade the sharks and every thing is normal again I would like to add an angel fish or something nice and 1 of my LFS has a 5-6 inch Koran that has been there since 3/5 and it eats just about anything or I was wanting to purchase a 5 inch specimen from the marine center what do you think?
<A good idea in my estimation. Likely to add a great deal of color, interest to your system.>
Also do the angels ever pick on the sharks <Yes... some species more than others... of sharks and angels... but not a huge risk, worry> and if it is not good for an angel I was thinking a Sohal and blonde Naso what sounds better to you?
<I'd rather the Angel. More intelligent, interesting behaviorally.>
and thanks for all the help you have given to me
Pam Reinsmith
<You're welcome. Bob Fenner>

Coldwater Shark out, Majestic Angel in
Hello bob,
Yes I am finally getting rid of my leopard shark <Mmm, why, may I ask?> and am trying to find one more fish to put in my tank you suggested that an angel would be okay in my 125 gallon so I am thinking about getting one what would you suggest
besides an Asfur or maculosus because they do not get along well with my fish I was thinking an Annularis or emperor something with a lot of color <These are fine fishes... my coverage of marine Angels is on the WWM site> my LFS has a friend that has had a majestic in his sump of his reef tank for about 7 months and he is still doing great but he would like to get
rid of him would a 5 inch specimen be okay for my tank or is this not a good choice.
<One that has been around this long is a "keeper"... I would buy/try it. Bob Fenner>
Thanks for any help you can give me and have a good day.