This is a guest contribution from Joe Rowlett, one of the many talented fish geeks working the fish tanks atOld Town Aquariumin Chicago.
The taxonomy and classification of fish is not a subject that your average reefkeeper investigates of their own volition. There is a bewildering array of big words, and terminology to digest, and added to this is the lack of scientific consensus on the exact relationships within the fish tree of life.
Instead, it becomes incumbent upon the enterprising reefkeeper to consult the primary literature of scientific studies published in peer-reviewed journals, which are often inaccessible behind subscription paywalls. It is understandable why so few in the reefkeeping world, whether casual hobbyist or professional aquarist, have a real grasp of how the fish we keep are related to each other.
我看到的鱼类最多的鱼是各种小的底栖(即底部)形式。水产师的普遍趋势是将所有这些公认的相似鱼类统一的鱼类以Goby或Blenny的态度结合起来。但是这样做忽略了这些群体所采取的单独进化历史,以汇聚出来。
The 14 Families of fish we’ll be discussing are indeed closely related—being members of the ‘Percomorphaceae’, or perch-like fishes. These can be thought of as being the more evolutionarily “advanced” fishes. But to put this in perspective, nearly every bony fish collected for saltwater aquariums (except for eels, squirrelfish, soldierfish, lizardfish, pineconefish, flashlightfish, & coral catfish) are percomorphs. Looking at the entirety of the fish tree of life shows that these 14 Families of goby-like bottom-dwellers evolved from at least 5 separate lineages of fish.
Gobiids & Gobionellids
在过去的十年中,Gobies(Gobiidae家族)的分类发生了重大变化。传统上,这个群体是最大的鱼家族,有1,800多个描述的物种,但最近的进步已将该小组分为两个大家庭,Gobiidae(1200多种)和Gobionellidae(600多种),同时将以前的Microdesmidae(Microdesmidae)重新融合在一起(虫鱼)和翼虫(Dartfishes/Firefishes)。
结合这一组的最可观察的特征是将骨盆鳍融合到一个磁盘中,这是一种对底部居住鱼的有用适应,它紧紧地粘在其底物上。此功能不是通用的,因为它已经丢失了无数次 -Ptereleotris,Microdesmis,Amblyeleotris,Eviota,Asterropteryx。识别的同样重要的是背鳍,它与原本相似的Blennies和Jawfishes的汇合背鳍不同。有类似戈比的鱼确实有背鳍,但它们总是缺少真正的哥比的融合骨盆鳍。
There is unfortunately not any useful morphological character for delimiting the gobiids from the gobionellids. Even the subtleties that ichthyologists have teased out—head pore counts andpterygiophoreinsertion patterns—don’t stand up to rigorous examination. It is arguable what value there is in splitting these two groups apart to the Family level given their similarities, other than to indicate that they are each large and independent lineages of fishes. In fact, not all researchers have accepted the elevation of gobionellids to Family rank. The main difference that is relevant to the reefkeeping hobbyist is ecological: gobionellids tend to reside in estuaries, whereas gobiids are mostly saltwater.
Few gobionellids find their way into aquariums. The most commonly seen genus is likelyGnatholepis, which is typical of the family in leading an unspecialized life on sandy substrates. The CaribbeanOxyurichthysStigmalophius是一种大型而有吸引力的物种,可以罕见地出现(根据我的个人经验,这是一个胆小,精致的物种)。
gudgeons
与Gobiid/Gobionellids密切相关的是家族的Eleotridae,通常称为Gudgeons或Sleeper Gobies。与“真正的戈比”不同,埃特里德斯总是拥有未连接的,非保险的骨盆鳍 - 这些鱼往往会在底部游泳,但不直接在底物上。
Most gudgeons are freshwater or brackish, and are commonly seen in the freshwater department of your friendly neighborhood fish store. The only reef-associated genus isCalumia, which consists of four small, colorful species that have sadly yet to make it into our nano-reefs. These fish have great potential as an aquarium inhabitant, if only someone would go about collecting them.
Jawfishes
我看到最频繁的鱼类wi混淆th gobies are undoubtedly the jawfishes, Family Opisthognathidae. While they share a similarly elongate body and benthic habitat, this group is in fact far more closely related to the blenny families. Gobies (and the closely related Cardinalfishes) are thought to have diverged from the other fishes we’ll be discussing more than 120 million years ago, during the early Cretaceous. The non-gobyness of the jawfishes is driven home by the fact that the pelvic fins are not fused into a suctorial disk and the dorsal fin is not split.
毫不奇怪,业余爱好者在识别这一群体方面遇到了困难,因为鱼类学家也遇到了类似的困难。只有随着大分子数据集的出现,达成共识才达成共识,这是一组被称为Ovolentariae的普通水族馆鱼类的一部分(O - Vo - vo - len - tar - tar - tar - tar - ee - ee)。将这些鱼类联合的共同特征(包括丽鱼科,dottybacks,少女,格拉马斯,评估者,颚鱼和蓝果)是卵子上有粘性细丝的趋势,可以使它们沉积并守护起来。
Triplefins Blennies
The Family Tripterygiidae consists of 175 species of small blenniod fishes which resemble the Trimma and Eviota gobies. The most salient character to identify this group is alluded to in the family name, which comes from the Greek for “three fins”. The “three fins” is in reference to the unusual configuration of the dorsal fin, which is broken into three separate fins. Another important identifying character for this Family and the following blenniod Families is the presence of feathery appendages on the head known as cirri (singular cirrus). This is a speciose group with many colorful members that would make for excellent nano-fish, but their tendency to reside in algae-dominated habitats has led them to be seldom collected for aquaria.
Labrisomid & Clinid Blennies
The Family Labrisomidae consists of 119 species of blennioid fishes found throughout the Western Atlantic and Eastern Pacific. Labrisomids have scaled bodies and more spines than soft rays in their dorsal fin. Labrisomids are uncommonly collected, with the Diamond BlennyMalacoctenus boehlkeiand the Saddled Blenny M. triangulates being most common.
Their closest relations are a suptropical group of algae-dwelling blennioid fishes known as kelpfish, Family Clinidae. The only tropical clinid, the Indonesian WeedfishSpringeratus Xanthosoma, is rarely collected for aquaria.
Sand Stargazers
One of the least blenny-like of the blennioid fishes are the Sand Stargazers of the Family Dactyloscopidae, whose 48 species are mostly found in Neotropical waters. The common name of Sand Stargazer alludes to the habit of burying in the sand with only the upwardly pointed head exposed—a behavior shared by the True Stargazers of the unrelated and non-blennioid Family Uranoscopidae. The convergence of form exhibited by these two Families is deceptive; the subtle differences in body and fin shape clearly show that these two fishes are only distant relatives, having diverged roughly 112 million years ago! Sand Stargazers are rarely available and are often mislabeled as uranoscopid stargazers.
Pikeblennies,藤壶Blennies,Sailfin Blennies
The 97 species of the Family Chaenopsidae are found throughout the Eastern Pacific and Western Atlantic and exhibit a remarkable variety of forms. Identifying characters are a scaleless body and a dorsal fin that is enlarged anteriorly and which has more spines than soft rays. The Sailfin or Signal Blennies (Emblemaria) are common Floridian imports that make for lively nano-fish.
From the same part of the world comes the Pikeblenny (Chaenopsis alepidota), which looks very un-blennylike in lacking cirri.
Also lacking in cirri is the uncommonly seen Wrasse Blenny (半肢体). This species mimics juvenile bluehead wrasses, and in doing so has lost its cirri to better its subterfuge.
Combtooth Blennies&Fangblennies
With 400+ species—many of which are commonly kept in aquaria—the Family Blenniidae is the largest of the blennioid families. These are scaleless fish which have more soft rays than spines in their dorsal fins. There are two groups in this family that differ quite markedly in behavior. The more predatory Subfamily Blenniinae contains common species like the Fangblennies (Meiacanthus), which are active swimmers that possess venomous canines.
The Combtooth Blennies of the Subfamily Salariinae contains mostly benthic, non-venomous, algae-eating fish. While these algae-eating blennies are enormously popular, it is often overlooked how aggressive they can be in small aquaria. I’ve seen them damage and kill numerous wrasses and anthias. They are also unlikely to directly help with theBryopsisandDerbesiaalgae outbreaks that aquarists frequently purchase them for, as their preferred algal diet consists of shorter, tastier greens.
Dragonets
小龙的190种,家庭Callionymidae, are confusingly known as Scooter Blennies and Mandarin Gobies. Dragonets are quite goby-like in having a split dorsal fin, but the unfused pelvic fins immediately identify this as a non-goby. The split dorsal fin and lack of cirri indicate these fish are not blennies either. So what is this non-goby/non-blenny fish related to?
A surprising result from recent molecular studies has been the grouping of dragonets with the seahorses and pipefishes. This is an arrangement which intrinsically makes sense to aquarists, as both groups have small mouths and a very deliberate method of feeding. To think of a dragonet as a fat-bodied pipefish does not stretch the imagination too far, especially given the similarities required to care for them.
Parapercis
Parapercis,Pinguipedidae家族有时会在水族馆贸易中可用 -P. ClathrataandP. schuainslandiibeing most common. These fish have a very goby-like demeanor, though oddly enough they have appeared with the common name of “Sandhopper Blenny”. This is a rather egregious misappropriation of the name “blenny”, as there is little about this fish that is blenny-like, nor is it very closely-related to them. These fishes are closest cousins to the True Stargazers. The alternate common name Sandperch is a better choice for these sand-dwelling, perch-like fish.
Osopsaron & Pteropsaron
这些鱼虽然在外表上有点像Goby,但肯定不是Gobies。幸运的是,在礁石世界中,这种混乱并不重要,因为这些深深的鱼类尚未为水族馆收集。这些更合适的通用名称是SignalFishes或Sand-divers。
The exact placement of these genera has bounced around recently, with the current consensus being that they are most closely related to the sand-divers of the genusTrichonotus, Family Trichonotidae, which may or may not be related toParapercis。
Pholidichthys
The two species ofPholidichthys, Family Pholidichthyidae, are neither gobies nor blennies, but naturally go by the names of Engineer Gobies and Convict Blennies—a classic example of a fish’s common name giving no indication of its true relationship to its piscine brethren. Not surprisingly, this is another fish that has long been clouded with uncertainty as to its exact derivation. It is only in the last few years that its placement has been supported near the base of the Ovolentariae (the group of sticky-egg layers that includes blennies, dottybacks, etc.). It is the speciose freshwater Cichlidae that are its closest relations. Thus this non-goby non-blenny appears to be a near-cichlid instead.
… … …
Hopefully this taxonomic excursion will help in some small manner to clear up the confusion regarding these fishes. Haphazardly tossing around names like “goby” and “blenny” is in poor taste for the discerning reef aquarist. Cheers.