I bought a mixed pack of beads which had these goldfish in - and that led to the idea of a necklace using them with green beads (plants) and clear/frosted glass beads (water).
I started with clear illusion cord, and spacing the beads out - but it became clear that knotting the cord was hard to do evenly, and then the beads didn't hang well. So I decided to use bugles and rocailles to space the beads instead. It was quite a challenge to get the three strands to hang properly, so I did lots of threading and re-threading.
Step 1: What You Need
Beads - I used 4 goldfish and assorted green glass and clear/frosted glass beads
Rocailles - I used large green silver-lined and small clear silver-lined
Bugles - I used assorted clear and silver-lined (from a mixture I had)
Clear illusion cord
5 three-strand spacer bars
2 jump rings
Step 2: Decide on Your Arrangement
I arranged the beads on my bead board - there's an instructable if you want one like this.
The photo shows my initial arrangement, but in practice it was clear that the goldfish needed to be in the centre sections only, and I reduced the number of large beads too.
Step 3: Thread Your Beads
Thread your beads, starting with the innermost strand. I had gaps between the spacer bars of about 6.5 cm in the innermost strand, 7 cm in the middle strand, and 7.5 cm in the outer strand.
I tied a stopper (figure of eight) knot about 30 cm from the end of a 120 cm piece of cord, then threaded the spacer bars and the beads, and tied another knot after the final spacer bar when I was happy with the arrangement of the strand. Then I did the middle strand, and finally the outer strand.
Step 4: Glue Knots to Secure
I applied superglue to the stopper knots and slid a large rocaille up to cover the knots, then left to dry.
Then I threaded rocailles and bugles on each thread until the necklace was the right length. Again the inner strand was slightly shorter and the outer ones slightly longer.
I tied stopper knots at the end of each strand and superglued them.
Step 5: Add the Clasp
I used a calotte to cover each stopper knot, crimped with pliers, then trimmed the excess thread. The three calottes were threaded on to an opened jump ring, along with one half of the clasp. Closing the jump rings finished the necklace.