这回我们发现了新的珊瑚寄生虫

旧文，po到公众上来

前段时间我们实验室发了一篇新文章就是讲发现了一种新的专吃鹿角珊瑚的寄生虫[1]，就是鱼友说的那个小黑虫，或者翻缸虫（听名字就挺猛的），我们很早就发现了那个虫子，我记得是我发现了差不多半年以后cmf上才开始有人说中了这个虫子，但是也是一直拖着，第一篇论文今年年中才发表在水产领域顶刊aquaculture上（二区，top），然后就问coral magazine德文版的主编Daniel knop，问他有没有兴趣登个这个寄生虫的文章，他说有兴趣，其实我开始没有意识到他是德文版的主编，还以为是英文版的，但是都说了也不好意思拒绝人家了，就写了个英文版的给人家，他翻成德文先登到了德文版coral magazine上，还跟我吹牛说，coral magazine有四五种语言的版本，德文版才是主刊，一般都是最好的文章德文版先登，然后英文版再登，所以在11-12月刊德文版见刊以后，英文版直到20年1-2月刊才见刊。没先写中文一个是反正最近国内也没小黑虫感染也不着急，刚刚好现在这个时间印尼可能很快就要重新开始允许出口珊瑚，这个虫子可能又要卷土重来，时间点掐的刚刚好。一个是就跟那些艺术电影一样，先得国外得个奖，国内票房才会比较好一样。而且我现在觉得国外的名气可能比国内的有用一些，效果好的话，以后可能都先写给coral magazine德文版再绕一圈回来了。所以讲实话这个文章也蛮有意思的，我写成英文版再被翻译成德文，再按着德文翻译回英文，然后我自己再把那个英文版翻回中文，简直是毅种循环。

说回正题，本来想就翻译一下就完事了，但是我翻译完觉得这个纸媒时代的又臭又长的描述方式可能大伙看起来不太习惯，而且这样翻译了两遍以后不知道为什么内容有些被删掉了，干脆就重新写一遍好了，想看coral magazine原文的我也翻译好了附在了后面。

最早在2016年的时候，我就发现几颗印尼买的鹿角好像不太对劲，有AEFW的啃食痕迹，有非常类似AEFW的卵块，但是上面还有一堆游来游去的黑色小虫子，我非常奇怪这个东西到底是什么，先在各种养珊瑚的论坛和网站都查了一遍没有任何信息，然后去查了一下珊瑚寄生虫的文献也没有提到过类似的东西，这时候我就基本确认是新种了。然后就开始做了一些工作。

很多鱼友对这个虫子到底属于什么类型的动物有争论，最神奇的是看到有鱼友说这个是一种甲壳动物，其实拿出来捏一捏就知道这玩意完全是软的怎么可能是甲壳动物。我们在文献里面把这个虫子叫做NAEFW，就是new Acropora eating flatworm，嗯，这玩意跟AEFW一样，也是属于扁形动物门的，所以也是flatworm，但是英文都叫flatworm，中文实际上有两种叫法，一般扁形动物门里比较扁的那种叫扁虫，不扁的一般叫涡虫，这东西横截面实际上是圆形的，整体其实是个蛋状的，所以是涡虫。我们拍了一些电镜做了一些我们能做的分类学工作，目前我们可以确定这个涡虫是三肠目（Tricladida）或者是原顺列目（Proseriata）。因为我们实验室主要研究方向是珊瑚对气候变化的响应机制，所以对涡虫分类学不是很熟悉。

这个虫子有很多跟AEFW相似的地方，首先是专门吃鹿角珊瑚，而且都是从底部开始吃起，啃噬痕迹还很类似，都是一个一个白点，居然卵都很像，都是黄色的不到一毫米的扁圆形。但是成体应该说区别就非常大了，不像AEFW肉眼很难直接看见，小黑虫这玩意很容易肉眼就看那一个小点游来游去的，一般体长不超过3mm，而且可以伸缩。而且AEFW基本上不具有游泳能力，也能在水里扭啊扭的，但是一般是不游泳的，这个小黑虫体表有纤毛覆盖，游泳能力还是非常强的，如果你把水流全部关掉这个虫子很有可能会游出来，尤其关灯之后，所以这个虫子的传染速度比AEFW要快很多，不过也是因为这样，一个清除这个虫子最基本的办法就是直接拿出来用滴管直接吸海水冲下来，不过这样只能治标，具体治理办法后文会讲。刚说卵块跟AEFW很像，但是仔细观察其实是不太一样的，AEFW喜欢产比较密密麻麻的一坨卵块，这个小黑虫的卵一般更加散一些，但是卵的大小形状颜色真的几乎是一模一样，而且都是多胚胎的，AEFW一个卵里面一般是2-4个幼虫，这个虫子我们目前观察的也差不多是2-4只比较常见。

幼体出生以后体内没有虫黄藻是半透明的，只有头部有几个眼点，看起来是四个其实是六个，有两个连一起的，看起来跟眉毛似的，所以我一直想把种名定成蜡笔小新，可惜的是我们自己没有能力定种，找了一个专门做涡虫的老师给他寄了一些样品去，但是他要活的才能定种，他又不会养这个，然后本来准备再寄一些过去的时候这虫子居然被我师弟养死了，这世界上的事情就是这么诡异，明明一个泛滥成灾弄都弄不死的玩意一要做实验就给湿弟养死了，本来我还在纠结是以我女朋友的名字命名还是用蜡笔小新命名还是中规中矩一点命名的，这下都被我师弟搞没了，现在我们在用留下的一些固定的样本做一些形态学和分子的工作看能不能弥补一下，当然各位鱼友如果有活体的虫子的话能够寄给我就再好不过了。

现在印尼禁止珊瑚出口以后基本上就慢慢看不到有谁说中了这个虫子了，所以印尼的渔业部长禁止珊瑚出口导致了另一个国家的科研狗没法给一个寄生虫定种，也是很蝴蝶效应了。当然我上面说的不代表虫子一定是从印尼来的，因为珊瑚都是放在一起的，很难讲到底是从哪个地方来的，但是目前最有可能的是印尼。19年上半年的珊瑚美国珊瑚网站REEF BUILDERS也报道了美国有鱼友发现了这个虫子[2]，

这虫子居然花了这么久才传播到美国去也是很神奇，不过也就是这个原因，才有机会第一次由中国的科研狗首次发现一个比较重要的珊瑚寄生虫，算是我们比较走运吧。发现之后的那段时间我一直很怕别人抢了先，毕竟科研这种东西第二是没什么太大用的，所以一直关注有没有别人发现这个，有鱼友中了这个虫子问我我也会告诉他尽量不要告诉别人，尤其搞科研的，还是怕同行抢了先，目前看来似乎还根本没有同行关注这玩意。。。。算是想多了。

讲了那么多大家最感兴趣的肯定还是如何杀灭这个虫子。最开始我们用常用的氯化钾和coral RX来试着杀一下看，发现完全没有作用，所以常用的检疫方法可能完全没办法预防这个虫子，这也是这玩意比较麻烦的地方。后来我们尝试了很多种药物以后发现高效氟氯氰菊酯是效果比较好的，杀灭快，也不伤害珊瑚，但是也不能杀卵，还是得靠封的。所以具体操作要这样子，滴一滴4.5%的高效氟氯氰菊酯乳油到一升海水中，搅匀，然后把珊瑚放进去泡10分钟，然后摇一摇使虫体都脱落，用干净海水涮洗珊瑚几次，然后用阿隆发把底部的卵块封起来。每七天泡一次，重复几次保证杀灭干净。高效氟氯氰菊酯是一种合成拟除虫菊酯，用起来一定要小心（主要是要戴手套）。目前这些杀灭实验的数据还没正式发表，具体数据会在下一篇科学文献里面发表。

参考文献：

[1] Wang, Q., Yan . Li, X. Zheng (2019): Morphological and histological characterization of a new Acropora-eating fl atworm: A potential threat to captive acroporid corals. Aquaculture 512: 734384, DOI: 10.1016/j.aquaculture.2019.734384.

[2] (October 2019): reefbuilders.com/2019/0

以下是coral magazine原文：

New Acropora -Eating Flatworm Discovered

The flatworms that feed on Acropora , multiply in the aquarium, and can cause serious damage by consuming coral tissue have been known for years. Identified as Prosthiostomum acroporae (originally described as Amakusaplana acroporae ), it is often referred to informally as the dreaded “AEFW” or “ Acropora -Eating Flatworm.” Now a second flatworm that also specializes on staghorn corals has been discovered in China. Biologist Yan Li reports on it for CORAL :

那些专吃鹿角珊瑚并且可以在鱼缸里繁殖的的扁虫已经广为人知，他们在鱼缸里大吃大喝造成巨大的破坏。这些扁虫的学名被叫做 Prosthiostomum acroporae (一开始被叫做 Amakusaplana acroporae )，一般俗称AEFW，或者是“ Acropora -Eating Flatworm.”现在新发现了第二种专吃鹿角的珊瑚，由生物狗李琰介绍给coral magazine:

When I contacted Koralle Editor Daniel Knop and asked him if he was interested in the latest discovery at our laboratory in Xiamen, China—a flatworm that specializes on Acropora as food—he probably thought something like, “This scientist is from another planet; he thinks the old Acropora predator is a new discovery.” His answer to me was, “We had a report on Prosthiostomum acroporae in KORALLE in 2002, when it wasn’t yet scientifically described.”

当我一开始联系 Koralle （coral magazine德文版）的主编并且问他对我们实验室新发现的一种专吃鹿角珊瑚的扁虫感兴趣的时候，他脑子里可能想的是“这些科研狗搞科研都搞傻了吧，居然觉得AEFW是一种新发现”，所以他回复我“我们在2002年就在 Koralle 上报道过AEFW了，比学术界最早的报道还要早”。

Admittedly, it isn’t uncommon for reef aquarists to encounter a new species from the coral reef before we scientists do. But on this occasion, we clearly got there first, as our laboratory recently identified another Acropora eating trophic specialist among the flatworms that could also spread into the aquarium hobby.

的确，对于珊瑚领域来讲爱好者比科研狗发现新品种还要早也不是什么很罕见的事情。但是这回，还是科研狗比较快，我们发现了另一种新的能在鱼缸里大量繁殖的吃鹿角的扁虫。

It is, however, hardly surprising that people immediately think of Prosthiostomum acroporae when terms such as “flatworm” and “ Acropora predator” appear together, and there is possibly also mention of dark yellow eggs on coral skeletons that have been eaten bare.At first glance, it is difficult to see that it is another parasite. On closer inspection, however, a number of important differences in detail are noticeable.

当然，一听到“扁虫”，“专吃鹿角”，珊瑚基部有黄褐色的卵块的时候，很难不想到是AEFW，但是很多其他的特征让区别他们非常容易。

Body structure

I would like to select the abbreviation NAEFW (“new AEFW”) for our new discovery. Since both belong to the phylum Plathelminthes, they both fall under the grouping of polyclad flatworms. However, the body shape of the new worm isn’t flat. Viewed from the side, it is oval-shaped. The body length of an adult specimen barely exceeds 3 mm, and it is thus significantly smaller than the up-to-8-mm-long AEFW. In addition, the NAEFW occasionally contracts its body to be only about a millimeter long. This is regularly seen in dead specimens. Regardless of their size, however, these two species can be distinguished by their body shape alone if you look very closely.

身体结构

我们实验室把这个新的扁虫叫做NAEFW (“new AEFW”)。虽然新扁虫和AEFW都属于扁形动物门，但是其实新扁虫的身体一点都不扁。实际上从刨面看，它还是圆形的，整个身体其实是蛋状的（所以其实并不应该叫扁虫，中文中对扁形动物门中的动物有两种叫法，一个叫扁虫，另一个身体不适那么扁的通常叫涡虫，而英文对应的就只有flatworm一个词，以下就叫做涡虫）。这种虫子体长一般不超过3mm，跟能长达8mm的AEFW区别很大。而且NAEFW可以缩到1mm长，当然这样一般是死了。

In the aquarium, however, this size difference does not always help to distinguish the two species from each other, as the AEFW is partially transparent and distributes the zooxanthellae of its host coral evenly in its body so that it is optimally camouflaged and hard to see. The NAEFW also stores the symbionts of the host in its body, but in a special, sac-like cavity. As a result, adult specimens look like purple-brown dots moving around on the coral skeleton. Once you have developed an eye for the typical appearance of this infestation on the lower part of an Acropora , this parasite is easy to spot. Juveniles of the new flatworm species are far more difficult to detect, as their tissue is largely transparent and no host zooxanthellae have been stored yet. The only thing you can see easily is the eyes, which appear as black dots. There are three of them on each side of the body, so these worms have a total of six eyes, but the two upper eyes on each side are connected so that they look like a short black line. This line always reminds me of an eyebrow, and it lends the creatures a certain similarity to a comic figure very popular here in China. Around our lab it is known as the Crayon Shin-Chan Flatworm , after the animated show.

体型大小也不一定能帮你区分开二者。因为AEFW有虫黄藻保护色很难以发现。NAEFW也有虫黄藻，但是虫黄藻大量的存储在囊中，让虫体在珊瑚上看起来是一个褐紫色的小点在飞快的移动。所以你有一定了解以后检查珊瑚的基部应该是很容易区分的。但是NAEFW的幼虫却难以发现的多，因为他们体内还没有虫黄藻所以还是半透明的。所以他们唯一能被看见的部分只有眼睛，它们的眼睛是小黑点状的，一边三个，总共有六个。不过外侧的两个看起来连起来了像是眉毛一样。所以我一直想把这个虫子命名成蜡笔小新。

Behaviors

If you turn off the current in the aquarium completely, the worms often move into the open water and swim. Their entire body is equipped with cilia, which they can use to move in the water column. This means that these flatworms do not attach anything like as firmly to the coral as AEFW, and this means a coral can be freed of them by exposing them to a powerful pump stream.

行为

当你把鱼缸中的水流完全关掉时，这种虫子经常会大量游动到水中来。它们的体表有一层纤毛，所以可以游泳。这意味着这种虫子不像AEFW只能贴在珊瑚上，所以它们可以通过水流快速传播到缸里的所有地方。

In a laboratory experiment on the infection, Acropora species and four additional stony-coral species were tested to find out how species-specific the NAEFW flatworms were in selecting their host corals. Among our SPS corals maintained long-term, at least ten different species of Acropora were damaged, but in not a single case were corals of the genera Montipora , Seriatopora, Stylophora , or Porites affected. This strongly suggests that the worms specifi- cally attack Acropora corals.

而在我们做的侵染实验里面。我们使用了两种鹿角珊瑚和四种其他属的石珊瑚来看这种虫子到底是不是特异性只吃鹿角的，答案当然是确实是的。做侵染实验之前，我们在感染了这个虫子的缸里有十几种鹿角珊瑚全部被感染了，而在同一个缸里的 Montipora , Seriatopora, Stylophora 和 Porites 这些属的珊瑚全部都没有被感染，所以我们基本上确定这种寄生虫是专门吃鹿角的。

Normally the NAEFW, like the AEFW, attaches to the underside of Acropora corals in order to eat polyp tissue there. According to my observations, however, the new species spreads more rapidly than the one already known, mainly because of its ability to swim through the open water and reach other corals. Once the worms are swimming in the open water, they sometimes exhibit phototaxis, swimming towards a light source, but this isn’t always observed, and here too more information is required.

通常来讲，这个新种的NAEFW跟AEFW一样，也是粘附在鹿角珊瑚的基部吃珊瑚的组织。但是这种新种虫子传播更快，可能是因为他们能够游泳。有趣的是，当它们游在水中的时候有时候会表现出趋光性（黏在珊瑚上的时候完全不会），但是有时候又没有趋光性，不是很清楚原因需要进一步研究。

Source of infection

At the end of 2016, we obtained several Acropora corals from Indonesia, and some of them were infested with NAEFW. It was a few months before we first discovered that this parasite must be a new species, one unknown to science. Ever-increasing numbers of SPS aquarists are reporting on a Chinese aquarium forum called China Marine Fish (CMF) that their Acropor a corals have been attacked by a parasite they have never seen before, and they usually describe the parasites as “small black worms.” The majority of the corals reported come from Indonesia; the remainder from Australia. Because the retailer always keeps all the corals in the same sales tank, it is difficult to say for certain where the worms came from. In my estimation, however, Indonesia remains the prime suspect.

Most aquarium-hobby retailers in China have not received Acropora corals since Indonesia’s ban on the export of stony corals in 2018, and since then Chinese aquarists haven’t encountered any new cases of infection. This reinforces the assumption that the provenance is Indonesia, but it isn’t proof. Prevention is particularly important given the high infection and reproductive rate of NAEFW, and in order to arouse sufficient attention, I am first reporting this discovery in KORALLE and its foreign language partners such as CORAL , so as to reach readers in Europe and America before I publish my experiences in Chinese.

来源

在2016年年末的时候，我们观察到几颗来自印尼的鹿角珊瑚上有被一种寄生虫感染。我们花了几个月确定这种寄生虫是一种新种，没有任何科学文献记录过。然后一段时间我在CMF论坛上发现越来越多的鱼友发现他们的鱼缸感染了这种从来没见过的虫子，他们把它叫做”小黑虫“。被感染的珊瑚大部分来自印尼，小部分来自澳洲，因为商家都是把珊瑚放一起的，所以很难确认这虫子到底是从哪来的。以我估计，印尼还是最有可能是来源地，自从印尼出了珊瑚出口的禁令以后就几乎没有任何新的感染情况出现，这是个佐证，不能最终证明什么。但是无论如何，因为这种虫子感染传播非常快，所以预防工作是必须得做好的。所以我先给coral magazine德文版写了这个报道，然后转述到了coral magazine，来提醒欧美的鱼友进行预防。

Countermeasures

Although I have a lot to report on the behavior and taxonomy of these new Acropora parasites, the most interesting thing for aquarist readers is likely to be the measures taken to combat them.

Initially, as a test, I used two medications that are widely available for the quarantine of corals and are suitable for the treatment of most coral diseases: potassium chloride (KCl) and a preparation called Coral RX. Both were ineffective against the flatworms, which is why NAEFW survives conventional quarantine procedures without difficulty. It became apparent that glutaraldehyde was able to kill the flatworms. That was the good news. The bad news was that, unfortunately, it killed the coral too.

Next, we experimentally tested numerous pesticides (unpublished data) and found that beta-cyfluthrin, an active ingredient in many plant protection products, kills the flatworms, but doesn't noticeably affect the health of corals.

Use one drop of 4.5% beta-cyfluthrin oil emulsion in one liter of sea water, homogenize the mixture, and immerse the affected coral for ten minutes, during which time it should be moved vigorously so that the flatworms detach from the host and swim away. Next, rinse the coral several times in clean seawater and then drip the gel-like beta-cyfluthrin oil emulsion directly onto any detectable flatworm eggs and let it take effect. This treatment procedure, which could also be tried on P rosthiostomum acroporae , should be repeated several times at seven-day intervals. Cyfluthrin is a synthetic pyrethroid insecticide and must be handled with care.

Based on the structure of the cilia and other organs, which we investigated with the aid of a scanning electron microscope, it can be unequivocally stated that the NAEFW belongs the orders Tricladida and Proseriata. Because our laboratory concentrates mainly on the effects of climate change in corals, however, work on flatworm systematics takes somewhat longer. Even so, molecular genetic investigations are already in progress, and the results will be published in a scientific paper.

—Yan Li, Xiamen University, People’s Republic of China

如何杀灭

我知道我逼逼了一大堆分类学的信息，大家最感兴趣的还是如何杀灭这玩意。

最开始，我用了两种最常用的检疫药物来处理这个虫子：氯化钾和coral RX。结果居然一点都不管用，所以通常的检疫流程可能对这玩意一点用都没有。然后我试着用戊二醛来杀灭这个虫子，好消息是确实能杀死这个虫子，坏消息是，珊瑚也会死。

所以接下来我尝试了一堆的杀虫剂农药（未发表数据，会在下一篇学术文献里面发表）来杀灭虫子。结果发现高效氟氯氰菊酯能够杀死这个寄生虫又不伤害珊瑚。

具体操作是这样的，滴一滴4.5%的高效氟氯氰菊酯乳油到一升海水中，搅匀，然后把珊瑚放进去泡10分钟，然后摇一摇使虫体都脱落，用干净海水涮洗珊瑚几次，然后用阿隆发把底部的卵块封起来（这里他们在翻译过程里不知道咋搞的出现了错误，他们写的用高效氟氯氰菊酯的胶来封，实际上我写的是用阿隆发来封。。。应该是不存在高效氟氯氰菊酯胶这种东西的）。这个处理流程也可以用在AEFW上，每七天泡一次，重复几次保证杀灭干净。高效氟氯氰菊酯是一种合成拟除虫菊酯，用起来一定要小心（主要是要戴手套）。

最后说一下，根据我们用电子显微镜拍摄的纤毛和器官结构，目前我们可以确定这个涡虫是三肠目（Tricladida）或者是原顺列目（Proseriata）。因为我们实验室主要研究方向是珊瑚对气候变化的响应机制，所以对涡虫分类学不是很熟悉，需要更多的研究来进行分类。目前分子上的一些分类工作还在进行，会发在下一篇科学文献里面。

参考文献：

[1] Wang Q , Li Y , Zheng X . Morphological and histological characterization of a new Acropora -eating flatworm: A potential threat to captive acroporid corals[J]. Aquaculture, 2019, 512:734384.