. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOKINES1S IN SPONGE LARVAE 325. Figure 1. Brood chambers and embryos of Reneira sp. in various stages of development (a-c: light microscopy; d: scanning electron microscopy), (a) A section of the adult sponge that was attached at its lower edge to the coral substrate (arrowhead) shows a brood chamber (B ch) with embryos and larvae. Bar: 1 cm. Dermal surface, ds. (b) Embryos and larvae in a brood chamber clearly showing the pigment ring (PRg) at one pole. Bar: I mm. (c) A swimming larva showing the dark pigmented ring (PRg
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOKINES1S IN SPONGE LARVAE 325. Figure 1. Brood chambers and embryos of Reneira sp. in various stages of development (a-c: light microscopy; d: scanning electron microscopy), (a) A section of the adult sponge that was attached at its lower edge to the coral substrate (arrowhead) shows a brood chamber (B ch) with embryos and larvae. Bar: 1 cm. Dermal surface, ds. (b) Embryos and larvae in a brood chamber clearly showing the pigment ring (PRg) at one pole. Bar: I mm. (c) A swimming larva showing the dark pigmented ring (PRg) and long posterior cilia (LPC) at the posterior swimming pole (PP). and a protrusion at the anterior swimming pole (AP). Bar: 100 ;xm. (d) A larva showing the long posterior cilia (LPC). the unciliated posterior pole (PP). and the lines of short lateral cilia (SLC) arrested by fixation during their beat in metachronal waves. Bar: 250 fjm. rather than flagella because their motion is whiplike; they do not propagate quasi-sinusoidal waves (Alberts ct <//., 1989). Laboratory experiments on lan'iil phototaxis The larvae were maintained individually in 2 ml of /Lun-filtered seawater in 12-well multiwell dishes at room temperature (about 22 °C). At various times after release— 0. 2. 4, 6. 12. 24. and 48 hours—individual larvae were pipetted into a rectangular aquarium (15 X 20 cm) contain- ing seawater (Fig. 2a). Pipetting was not observed to affect the swimming behavior of the larvae. The rectangular aquarium (the test chamber) was immersed in seawater in a second aquarium, which was blackened on all but one side to reduce reflected light (after Wendt and Woollacott. 1999). Light from a cold light source (Volpi Intralux 5000) was passed through a diffuser made of acrylic plastic into the inner test chamber, such that a gradient of light was created in the horizontal direction from the front to the back of the test chamber (950 ju,A/ • photons
Size: 1877px × 1331px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
