. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. REPRODUCTION OF 253 en. int FIGURE 1. External views of zooids, showing gonads and brood pouch. All figures were drawn from living specimens with the aid of a camera lucida. A: P. fornwsuna. from left side. B: P. formosana, from right side. C: P. japonica, from left side. D: P. sagamiensis, from left side. E: P. sagamiensis, from right side. F: A sac-like zooid of P. sagamiensis, crowded with embryos after the resorption of the viscera, from right side, aa, atrial aperture; ba, branchial aperture; bp, brood pouch
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. REPRODUCTION OF 253 en. int FIGURE 1. External views of zooids, showing gonads and brood pouch. All figures were drawn from living specimens with the aid of a camera lucida. A: P. fornwsuna. from left side. B: P. formosana, from right side. C: P. japonica, from left side. D: P. sagamiensis, from left side. E: P. sagamiensis, from right side. F: A sac-like zooid of P. sagamiensis, crowded with embryos after the resorption of the viscera, from right side, aa, atrial aperture; ba, branchial aperture; bp, brood pouch with embryos; en, endostyle; es, esophagus; h, heart; int, intestine; mi, mid-intestine; od, oviduct; ov, ovary (immature); ps, post- stomach; pv, peduncular vessels; sd, sperm duct; st, stomach; te, testis (fully grown). and the most advanced at the distal end. Less than ten embryos develop within the pouch at one time. As soon as the tadpole stage is completed, the embryos leave the brood pouch and then the mother zooid through its atrial aperture as free larvae. In P. Japonica, the testis is divided into 6-10 wedge-shaped follicles which are arranged fanwise. Small sperm ducts issuing from respective follicles are united at the rivet of the testicular fan to form a common sperm duct. The ovary is located at the starting point of the common sperm duct (Fig 1C). The brood pouch of this species is quite similar in appearance to that of P. formosana. More than 10 embryos are found at a time in a zooid. Nearly mature embryos are often pushed out of the brood pouch into the peribranchial cavity. They soon hatch and escape from the zooid through its atrial aperture as free-swimming larvae. In P. .sagamiensis, the testis is subdivided into several irregular lobes Tokioka (1953) reported in the original description of this species that the testis is a large. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - co
Size: 1195px × 2092px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
