are chain cats sold for aquarists? they dont get very large when mature, correct? only about 2 ft or so? i saw some chainlinked dogfish sharks at the new england aquarium and i believe one was pregnant as it had a huge stomach and was constantly swimming in about a 600gl display. the male was just lying on the ground. are they cold water sharks? i know they are usually in very deep water with little light. any info would be great! i have a coral cat in a 300g now.