. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. HYDRA CHIMERA 293. FIGURE 3. Pattern of tentacle development on buds, (c) H. attenuate!. (a) P. oligactis (b) chimera, long- enough for each to produce five buds. Budding rates for these three strains were, respectively, , , and buds/day. Early morphogenesis, until basal disk formation, of the developing buds occurred at normal rates. However, chimera buds remained attached to their parents for an average of 8 days, while both parental buds detached after 3 days. Mature chimera buds were very small, averaging 1.
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. HYDRA CHIMERA 293. FIGURE 3. Pattern of tentacle development on buds, (c) H. attenuate!. (a) P. oligactis (b) chimera, long- enough for each to produce five buds. Budding rates for these three strains were, respectively, , , and buds/day. Early morphogenesis, until basal disk formation, of the developing buds occurred at normal rates. However, chimera buds remained attached to their parents for an average of 8 days, while both parental buds detached after 3 days. Mature chimera buds were very small, averaging mm in length (extended), whereas H. attenuate, buds average mm and P. oligactis buds averaging mm in length. Chimera buds did not them- selves begin to bud for 19 days, while parental buds budded after 10 (H. attenuata} or 11 (P. oligactis) days. Regeneration Polyps that had been fed six shrimps/day for 6 days were cut in half trans- versely and both parts allowed to regenerate, without feeding. Tentacle regenera- tion was assayed by the presence of tentacle rudiments. Basal disk regeneration was assayed by adherence to the dish. The chimeras (n = 3) and both parental species (H. attenuata, n = 8; P. oligactis, n == 7) regenerated tentacles from the proximal half in 2 days. The distal halves of chimeras and of H. attenuata regenerated basal disks in 2 days. How- ever, the P. oligactis proximal halves had not regenerated basal disks in 26 days. Thus, in basal disk regeneration the chimera resembled the epithelial cell parent. Feeding behavior The chimeras (as well as the two parental strains) showed typical (Lenhoff, 1969) feeding responses to Artemia. When shrimp touched the tentacles they adhered, indicating desmoneme nematocyte discharge, and were paralyzed, indicat- ing stenotele nematocyte discharge. Tentacles holding shrimp underwent consider- able writhing, and shrimp were brought to the mouth repeatedly. However, in the chimera the shrimp were never swallowed.
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
