4 Turbellarians are monoecious with the reproductive systems adapted for internal fertilization. And the monogenetic flukes (class Monogenea) are mostly ectoparasites of fishes.

涡虫是雌雄同体，生殖系统适于体内受精。单起源吸虫（单殖纲）大多是鱼外生虫。

Trochus pyramis Born is of gonophores.The male reproductive system is mainly composed of the spermaries and spermaductus, instead of mating and others glands.

摘要塔形马蹄螺为雌雄异体，其雄性生殖系统主要由精巢和输精管组成，没有交接器，也没有其他腺体。

4 Turbellarians are monoecious with the reproductive systems adapted for internal fertilization. And the monogenetic flukes (class Monogenea) are mostly ectoparasites of fishes.

涡虫同体的，生殖系统适于体内受。单起源的吸虫（单殖纲）大多鱼的外生虫。

Trochus pyramis Born is of gonophores.The male reproductive system is mainly composed of the spermaries and spermaductus, instead of mating and others glands.

摘要塔形马蹄螺为异体，其性生殖系统主要由巢和输成，没有交接器，也没有其他的附属腺体。

4 Turbellarians are monoecious with the reproductive systems adapted for internal fertilization. And the monogenetic flukes (class Monogenea) are mostly ectoparasites of fishes.

涡虫是雌雄同的，生内受精。单起源的吸虫（单纲）大多是鱼的外生虫。

Trochus pyramis Born is of gonophores.The male reproductive system is mainly composed of the spermaries and spermaductus, instead of mating and others glands.

摘要塔形马蹄螺为雌雄异，其雄性生主要由精巢和输精管组成，没有交接器，也没有其他的附属腺。

4 Turbellarians are monoecious with the reproductive systems adapted for internal fertilization. And the monogenetic flukes (class Monogenea) are mostly ectoparasites of fishes.

涡虫是雌雄同体的，生殖适于体内受精。单起源的吸虫（单殖纲）大多是鱼的外生虫。

Trochus pyramis Born is of gonophores.The male reproductive system is mainly composed of the spermaries and spermaductus, instead of mating and others glands.

摘要塔形马蹄螺为雌雄异体，其雄性生殖主要由精巢和输精管组成，没有交接器，也没有其他的附属腺体。

4 Turbellarians are monoecious with the reproductive systems adapted for internal fertilization. And the monogenetic flukes (class Monogenea) are mostly ectoparasites of fishes.

涡虫是雌雄同体的，生殖系统适于体内受精。单起源的吸虫（单殖纲）大多是鱼的外生虫。

Trochus pyramis Born is of gonophores.The male reproductive system is mainly composed of the spermaries and spermaductus, instead of mating and others glands.

摘要塔形马蹄螺为雌雄异体，其雄性生殖系统主要精巢和输精管组成，没有交接器，也没有其他的附属腺体。

4 Turbellarians are monoecious with the reproductive systems adapted for internal fertilization. And the monogenetic flukes (class Monogenea) are mostly ectoparasites of fishes.

涡虫是雌同体的，殖系统适于体。单起源的吸虫（单殖纲）大多是鱼的外虫。

Trochus pyramis Born is of gonophores.The male reproductive system is mainly composed of the spermaries and spermaductus, instead of mating and others glands.

摘要塔形马蹄螺为雌异体，其殖系统主要由巢和输管组成，没有交接器，也没有其他的附属腺体。

4 Turbellarians are monoecious with the reproductive systems adapted for internal fertilization. And the monogenetic flukes (class Monogenea) are mostly ectoparasites of fishes.

涡虫是雌雄同的，生内受精。单起源的吸虫（单纲）大多是鱼的外生虫。

Trochus pyramis Born is of gonophores.The male reproductive system is mainly composed of the spermaries and spermaductus, instead of mating and others glands.

摘要塔形马蹄螺为雌雄异，其雄性生主要由精巢和输精管组成，没有交接器，也没有其他的附属腺。

4 Turbellarians are monoecious with the reproductive systems adapted for internal fertilization. And the monogenetic flukes (class Monogenea) are mostly ectoparasites of fishes.

涡虫是同体，生殖系统适于体内受精。单起虫（单殖纲）大多是鱼外生虫。

Trochus pyramis Born is of gonophores.The male reproductive system is mainly composed of the spermaries and spermaductus, instead of mating and others glands.

摘要塔形马蹄螺为体，其性生殖系统主要由精巢和输精管组成，没有交接器，也没有其他附属腺体。

4 Turbellarians are monoecious with the reproductive systems adapted for internal fertilization. And the monogenetic flukes (class Monogenea) are mostly ectoparasites of fishes.

涡是雌雄同体，殖系统适于体内受精。单起源吸（单殖纲）大多是鱼。

Trochus pyramis Born is of gonophores.The male reproductive system is mainly composed of the spermaries and spermaductus, instead of mating and others glands.

摘要塔形马蹄螺为雌雄异体，其雄性殖系统主要由精巢和输精管组成，没有交接器，也没有其他附属腺体。