| Abstrakt: |
Davainea minuta Cohn, 1901, widely distributed and found in a number of Charadriiformes is reviewed and its synonymy with D. himantopodis Johnston, 1911 sustained. Himantaurus minuta (Cohn) Spasskaya et Spasskii 1971, is considered a synonym since shed, gravid proglottides continue to grow with subsequent breakdown of uterus and formation of egg-capsules. D. minuta is recorded for the first time from North American stilts Himantopus mexicanus (Muller) and avocets (Recurvirostra americana Gmelin. D. minuta shows variation in length and in the development of the reproductive system. In short specimens of seven or eight proglottides, the sixth is fully mature sexually; while in specimens of 16 or 17 proglottides, full sexual maturity is not attained until the 11th. The short specimens are from the duodenum and the longer specimens from the hind intestine. In cestodes the two reproductive processes: (a) asexual, in the formation of proglottides, or strobiliparity, and (b) sexual, in the maturing and production by proglottides of eggs, or oviparity, occur synchronously. The latter process predominates where food is plentiful, as in the rich pabulum of the duodenum, but in the hind intestine where there is little food, maturation and egg-production is a much slower process. |
