栉水母：分脊的内外结构 Ctenophore: The Comb-row Structure

它们属于无脊椎动物，有八个梳脊和许多纤毛，体型从1mm到1.5m不等，可谓是地球生物中的神奇杰作！经典动物学研究认为，它们没有刺细胞，靠粘细胞进行捕食。

These fascinating creatures belong to the group of invertebrates. With their eight rows of cilia and varying body sizes ranging from 1mm to 1.5m, they are truly a remarkable feat of nature! Unlike jellyfish in classic studies, they do not have stinging cells and instead use sticky cells to capture prey.

不过，它们也成为了许多动物的美味，例如大马哈鱼和海龟。不得不说，栉水母在生态系统中扮演着重要的角色。还有，它们是地球上较早的动物之一，神经系统的发育也是相当独特的哦！

However, they are still considered a delicacy to many animals, such as giant sunfish and sea turtles. It's safe to say that comb jellies play an important role in the ecosystem. They are also one of the earliest animals on Earth and have a unique nervous system that sets them apart.

栉水母动物的形态结构显然比海绵要复杂，从表型特征上来看跟水母（刺胞动物）差不多，它们都具有罩子式的基底膜（basement membranes），简单的肌肉、神经系统和部分感受器（感官，sensory organs）。

Ctenophores are structurally more complex than sponges, and they resemble jellyfish in appearance. They have a basal membrane, simple muscles, nervous system, and some sensory organs, similar to those of jellyfish. 

经典动物学中，刺细胞的存在将绝大部分刺胞动物和栉水母动物分开，现生极少数缺少刺细胞的刺胞动物都是后期退化的结果。

The presence of specialized cells called "cnidocytes" separates them from most other groups of animals, including ctenophores. The few cnidarian species that lack cnidocytes are believed to be a result of evolutionary regression.

但是，栉水母动物和刺胞动物又没有复杂到两侧对称动物的地步。它们只有两胚层。胚层之间存在的果冻样胶状物质称为中胶层（Mesoglea）。

Despite their complexity, ctenophores are not as symmetrical as bilaterally symmetric animals. They only have two germ layers, and the jelly-like substance between them is called "mesoglea." 

因此，有些较新的研究也把这两个门的动物与多孔动物、扁盘动物合成为“两胚层动物”，与“三胚层动物”相区分。

As a result, recent research groups these two animal phyla with poriferans and placozoas  are called as "diploblastic" animals, distinguishing them from triploblastic animals.

栉水母动物体型变异巨大，目前所知的种类体型从1mm 到1.5m 都有。大多数栉水母动物具有八个纵贯身体表面的“梳脊”（梳子背，Comb rows），在这些梳脊上有许多特殊的纤毛（Ctenes）,作为运动器官。栉水母动物可能是目前体型最大的使用纤毛（Cilium，复数 Cilia）作为运动器官的单体（非集群，Non-colonial）动物。

Ctenophores exhibit enormous variability in size, with species ranging from 1mm to 1.5m in length. Most ctenophores have eight longitudinal rows of cilia, called "combs," along their body surface. These combs are covered with numerous special cilia, known as "ctenes," which function as their primary mode of movement. Ctenophores may be the largest non-colonial animals that use cilia as their primary mode of movement.

栉水母动物没有刺细胞，与之相对的，粘细胞在它们身上起到捕食的作用。

Unlike most other groups of animals, ctenophores do not possess cnidocytes. Instead, they rely on adhesive cells for prey capture.

但反过来，栉水母动物也是许多水母的捕食对象。除此之外，大马哈鱼（Chum salmon，Oncorhynchus keta）和海龟（龟鳖目 Testudines）也以大量捕食栉水母动物而著称。栉水母动物是生态系统中重要的一环。

However, ctenophores are also prey for many jellyfish species. In addition, chum salmon (Oncorhynchus keta) and sea turtles (Testudines) are known to feed heavily on ctenophores. Thus, ctenophores play an important role in the ecosystem.

栉水母动物，这些透明而神秘的生物，总能引发我们的好奇心。它们的身体形状各异，有球形、卵圆形，甚至扁平形状。在黑暗的海洋深处，它们散发出美丽的荧光。虽然我们对这些生物了解尚浅，但它们在海洋生态系统中扮演着重要的角色。让我们继续探索这些奇妙的栉水母，为它们的揭开更多动物学的面纱吧。

The comb jellies, those transparent and mysterious creatures, never fail to pique our curiosity. Their body shapes vary, ranging from spherical to oval, and even flat. In the dark depths of the ocean, they emit beautiful bioluminescence. Although our understanding of these organisms remains limited, they play crucial roles in marine ecosystems. Let us continue exploring these fascinating comb jellies and unveil more of their secrets through the lens of zoology!