. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 268 LUCIENNE FENAUX 150 100 o O 50 Oj 50 Frequency. A65 M J A SON D J66 F M FIGURE 4. Evolution of the average size of oocytes (April 1965-March 1966). 25-30 meters deep (Fenaux, 1968a). The annual temperature variation at this depth during the period studied was from 12° C to 16°C. Figure 5 represents the monthly averages for these four years. Autumn is the main period of the appear- ance of ophioplutei (Fig. 5). At station 1, one to two ophioplutei are found for ten planktonic hauls. At station 2, the number of ophioplutei
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 268 LUCIENNE FENAUX 150 100 o O 50 Oj 50 Frequency. A65 M J A SON D J66 F M FIGURE 4. Evolution of the average size of oocytes (April 1965-March 1966). 25-30 meters deep (Fenaux, 1968a). The annual temperature variation at this depth during the period studied was from 12° C to 16°C. Figure 5 represents the monthly averages for these four years. Autumn is the main period of the appear- ance of ophioplutei (Fig. 5). At station 1, one to two ophioplutei are found for ten planktonic hauls. At station 2, the number of ophioplutei harvested is greater because of the transport of larvae by currents from the abundant population of Amphiura in the interior basin of the bay. In August and especially in October and November quite large numbers of larvae are occasionally observed, more than ten per hauls, whereas the average catch is, as for station 1, one to three larvae for ten hauls. Several ophioplutei have been collected in winter and spring. Nearly all the larvae collected were in the process of metamorphosis. DISCUSSION A histological examination of the gonads of A. chiajci has permitted me to state precisely the succession of the various stages of gametogenesis. After a period of sexual rest, the sex cells begin their development in winter (differentiation of the spermatids, growth of the primary oocytes) and come to maturity in spring. Reproduction takes place principally at the end of summer. Concerning spermatogenesis, there is a relatively important phase of accumu- lation of spermatozoa. If the differentiation of spermatogonia into spermatids takes place during an extended period, such activity is only observed in a small percentage of the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laborat
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
