YOU CAN TRY GERKINS , , CUKES REGULAR AND GUTA, MELONS . cantalopes , watermelons, the odds are against you but try anyway.

The scientific literature abounds with the results of unsuccesful attempts at crossing Cucumis metuliferus with others in the same genus. Believe me they've tried hard because this melon has some very desirable resistance characteristics that melon growers the world over would love to have. But so far zip! If the techos, who are so keen to cross it, haven't managed, I wouldn't even bother trying.
Being a melon it's probably an outbreeder which means there may well be a lot of genetic heterogeneity (lots of different combinations of genes). This gives you the possibility that in a field if kiwano you might strike a plant with sweet or at least less bitter fruit - maybe. But are you going to plant a field of kiwano on that basis?

Sorry, I've mislead you. Apparently, the kiwano is cross compatible with the musk melons, Cucumis melo L. which includes Muskmelon, Cantaloupe, Honeydew, and Sugar melon among others. However, I've not read the sources which claim this so I have no idea under what circumstances these crosses were obtained.
You could give it a go using both as 'mother'. In other words try Honeydew pollen on a kiwano female flower and the reverse.
Have you tried breeding before? If not and you decide to give it a go, look up the literature (internet is easiest) on how to cross melons or squash. You will need to know something about breeding a new plant in general as well. Can I suggest Carol Deppe's book 'Breeding your own vegetables' 2nd edition which you might get through your local library or bookshop if you want to buy. It's a great intro for the backyard gardener.
Good luck and please post updates regularly.

I bought a kiwano melon recently and was surprised by all the seeds! So of course I tried planting them in soil (for seeds) and today only 3 days after I have lots of seedlings.
Does anybody know how to take care of the seedlings? So far I have kept the soil covered with plastic on a warm windowsill.
happy easter...

Here's one paper that reported fruit formation but no viable seeds:

Euphytica 128(3): 371-374 (January 2002)

Incompatibility in diploid and tetraploid crosses of Cucumis sativus and Cucumis metuliferus
S. Alan Walters1 and Todd C. Wehner2

(1)Â Department of Plant, Soil, and General Agriculture, Southern Illinois University, Carbondale, IL, 62901-4415, U.S.A
(2)Â Department of Horticultural Science, North Carolina State University, Raleigh, NC, 27695-7609, U.S.A

Abstract  The African horned cucumber (Cucumis metuliferus Naud.; 2x = 2n = 24) contains genes that can confer resistance to many important cucumber (C. sativus L.; 2x = 2n = 14) pests [e.g., root-knot nematode, Meloidogyne incognita (Kofoid & White) Chitwood]. Cucumber is highly susceptible to this root-knot nematode species, and a recent screening of C. sativus accessions in the U.S. National Plant Germplasm collection did not identify sources of resistance. Thus, autotetraploids of Cucumis sativus and C. metuliferus were created to recover fertile resistant interspecific progeny. Autotetraploids were obtained at the highest rate when seeds were immersed in 0.5% colchicine for a period of 6 to 8 hrs. Treatment durations less than 6 hrs produced few tetraploids, and durations of 10 hrs or more were lethal to seeds or developing seedlings. Crosses between C. sativus and C.metuliferus were made using diploid and tetraploid lines in all possible combinations, including reciprocals. Fruit development occurred in crosses when diploid and tetraploid C. sativus were used as the female parent. However, seeds developed only in fruit of C. sativus (4n) ÃC. metuliferus (2n) crossings. Seeds from these crosses, however, were flat and not viable. No fruit development occurred in crosses where C. metuliferus was used as the female parent.

Success was achieved (apparently -- I haven't read the article) by making somatic hybrids -- fusing cells from two species.

Cucurbit Genetics Cooperative Report No. 14, July 1991
Selective methods for the recovery of somatic hybrids of Cucumis melo x C. metuliferus and C. sativus x C. metuliferus
M. Dabauza, L.A. Roig and V. Moreno (Spain)

Karl