One, they are not eels...they are from a family of fish called the Polypteridae and are commonly known as "Bichirs".
I expect that the 'dinosaur eel' is a Polypterus senegalus AKA Senegal bichir...the 'yellow dinosaur eel' I am not sure of, but based on what Petsmart has been stocking recently, I suspect that it is likely a Polypterus ornatipinnis, AKA Ornate bichir.
Here is my 'species overview' on the senegal bichir....I do not have one on the ornate handy, but it is much the same, savbe that ornate bichirs regularly attain lengths of 20"-26" and about as think as your wrist. A senegal or two can be kept in a 40 gallon wide or a trio will live happily in a 55, but an ornate requires 90 gallons and up.
Taxon: Polypterus senegalus senegalus
Common names: Senegal bichir, Cuvier's bichir, Nigerian bichir, Gray bichir
Range: Senegal, Nigeria, Gambia, Zaire
Size: Up to 13", but 10" is more common.
Water temp: 77ºF-82ºF
pH: 6.5-8.2
Sexing: Males have broader, thicker anal fins than do females, these fins will additionally increase in size during spawning.
Diet/Feeding: These are nocturnal, carnivorous predators that enjoy a varied, meaty diet, including earthworms, live feeder fish, krill, whitebait, beef heart, Mysid shrimp, prawns, small freshwater crabs, 'superworms' (Zoophobas morio), various insects, baby mice, frogs, and sinking, pelleted carnivore fish foods. Although most hunting/feeding takes place after dark, some species and individuals will happily pursue food during daylight hours as well.
Photoperiods: Aquarium lights on for 12-14 hours daily.
Spawning: Captive-spawning was first accomplished in the early 1960's, becoming commonplace in the early 21st century. Spawning of P. senegalus is not easy, but has been accomplished in the home aquarium.
Miscellania: Bichirs are capable of breathing atmospheric air (via a primitive lung similar to those of lungfishes) for several hours as long as they remain damp. Escapes from aquariums (usually done accidentally during regular surface-breachings or mating jumps) are not uncommon, so a secure glass lid is advised at all times. Bichirs pectoral fins share a similar skeletal structure to coelacanths (Latimeria sp.), and can use these fins for surprisingly efficient locomotion over terrestrial surfaces. Bichirs possess ganoid scales....hard, enamelled scales that hinge, rather than overlap...other fish with these scales include gars and paddlefishes.
There are 16 currently accepted species and subspecies of bichir, ranging in size from the small Polypterus retropinnis lowei at 10", to the imposing Polypterus endlicheri congicus which can reach a maximum length approaching 40". Bichirs were first discovered by European scientists during Napolean's incursions into Africa in the late 1700's, with the most recent subspecies being officially described as recently as 2000,and are regularly caught by native Africans for food. Of the 16 types known, 5-6 species are commonly found in the aquarium trade in North America, and can be differentiated by a number of means, the most simple of which are head-shape, pattern/colour, and the number of dorsal fin rays each fish possesses.
Some Husbandry Notes: Bichirs do best on substrates of sand, fine gravel, or bare tank bottoms, and like tanks with open spaces for free swimming, along with short, sturdy plants (bushy types work well), rockery and submerged logs for hiding, and a few floating plants/logs to provide cover security.
