龙巅
真正凶猛的并不是水虎鱼而是南美加拉辛牙鱼
2014-06-13 16:55:19
12
本帖最后由 非洲野鱼 于 2014-6-13 17:11 编辑
二楼有原版内容！可以自己去翻译！
如果把水虎鱼比作是猫咪！那么南美洲Hoplias就是食肉老虎，这才是真正可怕的食肉性鱼类！没有其他淡水鱼具有比一个更可怕的声誉食人鱼，但是正如许多鱼友了解的那样，他们其实是相当胆小的而且是紧张的，食人鱼水虎鱼喜欢咬其他鱼的鳍，而不是吞噬他们的整体。
然而，南美洲另一组的鱼却是更加贪婪和更加具有积极性，这就是亚马逊wolffishes家族，它们拥有有很多名字，包括Aimara，Guabina和Fasaco等等！
它们是characoid的子系列有16种，发现从哥斯达黎加到阿根廷的几乎每一个地方。因为狼牙鱼没有水的情况下也能生存，有人在干燥的季节发现Hoplias在排空水的池中。
在狼牙鱼家族：Hoplerythrinus unitaeniatus，最小，刚刚超过20厘米/ 8“，而最大（Hoplias aimara）将达到130cm/51”，超过30kg/66lb。狼牙鱼是很好的观赏鱼，令人惊讶的有趣的是与其他鱼类很团结友爱。这些鱼是耐寒性的很容易维护。
狼牙鱼子系列包括三个属，共16种。最大的群体是属Hoplias有11种，aimara和macrophthalmus是独立的物种。
接下来是Hoplerythrinus有三个品种，Erythrinus有两个。
因为法律的因素巴西，哥伦比亚和委内瑞拉不出口自己的狼牙鱼，所以渠道变窄。其他几个人都非常流行，并已很少被导出。假设一个水族馆狼牙鱼属于五个品种之一Hoplerythrinus unitaeniatus很容易被它的单横条纹的识别和伸长身体，从秘鲁和哥伦比亚偶尔出口。它可以保持在一个大型水族馆一所小型学校。
不像Erythrinus和Hoplias这些狼牙鱼狩猎小鱼群，尤其是characins，或追逐甲壳类动物和昆虫在基板或沿表面。所以他们更注重表面和主动比其他狼牙鱼。他们还可以在混养与其他大型鱼类，如鲶鱼，慈鲷和更大characins，如Myleus和Leporinus。Hoplerythrinus还吃干的食物，如小球冻干虾和昆虫，有时甚至片状食物。所有的狼牙鱼都是优秀的跳跃者所以必须的覆盖！Hoplerythrinus喜欢洪水区的栖息地或可以深入到淹没的平原或森林。
其他小品种Erythrinus erythrurus，通常被称为雷德芬狼牙鱼。幼年时候能显示它们侧翼诱人的红色，黄色和紫色，甚至影线标记了一个整体的棕色或酒红色。
鳍可以是鲜红色，黄色或白色。体形比Hoplerythrinus更粗壮，Erythrinus都比较孤独，所以群养需要大量的水族馆用做它们的藏身之地，让每条鱼有自己的领土和理想的洞穴。理想的混养鱼characins如Myleus和Metynnis或者体型大的慈鲷如Astronotus，
Erythrinus会吃活的鱼类，甲壳类，蠕虫和昆虫，不喜好冷冻食品。Erythrinus发现在沼泽的海岸线栖息地和浅水或森林深处。除了昆虫的幼虫，还有发现在它们的胃里有凤尾，Moenkhausia和Nannostomus。
最有趣的是Hoplias。通常只有三个品种出口，最常见的是H石斑鱼，这是出口最多了的亚马逊和奥里诺科河低地和来自秘鲁频频出口。水族店的任何狼牙鱼可能会属于这个特定的物种。颜色范围可以从斑驳的灰色至褐色，并根据产地，几乎是黑色的。幼体通常是重量更轻，有亮黄色或绿色的眼睛。
在自然界中它们是孤独的，几乎任何栖息地的滞销水域都有该种鱼类。该鱼生活在浅栖地，H.石斑鱼在5cm / 2“，猎食水生昆虫和小鱼。随着鱼的成熟长大他们变得不那么宽容对方，并会移动到更深的水域。 成体的H.石斑鱼过于激进需要更大的领土。
如同所有的狼牙鱼品种，水族箱的水化学是不太重要，因为这些鱼能适应几乎任何值的常用范围。Hoplias石斑鱼是懒惰的，只有当食物送上门。他们很积极兴奋在黄昏和黎明时段，所以保持照明让他们在白天表现出更多的活动。
即使打架受伤也会很快痊愈。大型野生Hoplias常常会严重受伤甚至眼睛，颌骨畸形和截肢，但似乎其他方面很正常。
性成熟阶段牙鱼会变的烦躁不安，两种性别的牙鱼可能要适应更长的时间！知直到相处融洽！繁殖的温度控制在28-29°C。雄性牙鱼会把繁殖的2000-10000黄色卵聚在一个浅坑并且守卫巢穴和幼虫，直到它们孵化开始在浅水狩猎小猎物。在水族箱中幼体牙鱼会立即吃卤虫无节幼体并且迅速成长还蚕食手足同类。
Hoplias的最新成员，也是第二大进口品种。它被称为Hoplias SP。
黑狼牙鱼喜欢更快的河流，特别是奥里诺科河的支流。身体更加粗壮，比H.石斑鱼整体色彩更均匀的黑色或深褐色。眼睛通常是同样黑暗。黑狼牙鱼似乎更喜欢大的虾和较大的鱼。在奥里诺科地区的胃内发现沼虾，几个慈鲷品种的幼鱼和较大规模的Leporinus。
Hoplias curupira更积极，H. curupira尝试吞下的鱼差不多与自身体积相当！繁殖行为没有发现在水族箱中，但很可能类似于其他Hoplias物种。
无畏王狼牙
最强大的Hoplias是狼牙鱼王：在aimara，或trair?o（Hoplias aimara及/或H macrophthalmus）。小鱼和青年成鱼鳃盖后面一个小黑点。他们是更大更容具有攻击性比其他狼牙鱼，在本质上是生活在水流湍急的河流，险滩的地方捕食任何移动目标绝对无所畏惧！
在水族馆H. aimara是很珍贵的，但不容易饲养。特别大的时候甚至会撞到了玻璃上撞破他们的颌骨，牙齿，甚至玻璃本身。它们可以超过30cm/12“ 可是当超过100cm/40”是最好饲养在丙烯酸储罐和留给专家。
Aimara有大而可怕的嘴巴，试图吞下任何和它同在鱼缸中的鱼类，包括大loricariids，其强大的颌骨甚至可以掰开。这些狼牙鱼也可以放在一起。如果水族箱尺寸允许，但很少咬对方。不过这个物种最好保持由专家谁可以处理这些大鱼的长期需求。不像其他的狼牙鱼H. aimara喜欢快速移动的水，可以在恶劣的水质条件更加敏感。在低氧环境中，他们变得非常不宽容对方。
移动狼牙鱼可能是危险的，因为鱼会咬你甚至跃出水面，他们3cm/1.2“长的牙齿可以穿透大多数的手套，轻松地刺破运输中使用的塑料袋。
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非洲野鱼
沙发 2014/06/13
本帖最后由 非洲野鱼 于 2014-6-13 17:07 编辑
本人根据外国网站的 practicalfishkeeping下面翻译的！
Predators: Hoplias, wolves of the water
Piranhas are pussycats! The Hoplias of South America are the predators to really fear, says Oliver Lucanus.
No freshwater fish has a more fearsome reputation than thepiranha, but, as many aquarists soon learn, these are actually quite timid. They get nervous when the aquarium is approached and prefer to bite pieces of other fishes’ fins rather than devour them whole.
However, South America is home to another group of fish that are far more voracious and much more aggressive. This is the family of the Amazon wolffishes and they have many names, including Trairão (sp.’Trai-ron’), Aimara, Guabina and Fasaco.
They are part of a characoid sub-family of 16 species, found from Costa Rica to Argentina in nearly every kind of water. Because the wolffish can breathe air it can survive where few others could. In the dry season it’s not unusual to find Hoplias the last survivors in an emptying pool.
The wolffish family has something for everyone: Hoplerythrinus unitaeniatus, the smallest, will reach just over 20cm/8”, while the largest (Hoplias aimara) will reach 130cm/51” and more than 30kg/66lb.
Despite their reputation wolffish can be good aquarium fish and are surprisingly interesting with other fish or in groups. Special rules apply, but these fish are hardy and easy to maintain.
Despite their reputation wolffish can be good aquarium fish and are surprisingly interesting with other fish or in groups. Special rules apply, but these fish are hardy and easy to maintain.
Classification
The sub-family consists of three genera, totalling 16 species. The largest group is the genus Hoplias with 11 species and we assume that H. aimara and macrophthalmus are separate species, although H. macrophthalmus may be a synonym.
The sub-family consists of three genera, totalling 16 species. The largest group is the genus Hoplias with 11 species and we assume that H. aimara and macrophthalmus are separate species, although H. macrophthalmus may be a synonym.
Next is Hoplerythrinus with three species, and Erythrinus with two.
Within their genus the species are similar and you’ll need to know where your fish were collected to have an idea of what species belong where. Brazil, Colombia and Venezuela don’t export their wolffish species, so the list narrows.
Several others are highly endemic and have rarely been exported. Assume that an aquarium wolffish belongs to one of five species.
Hoplerythrinus unitaeniatus is easily identified by its single horizontal stripe and elongate body, and exported occasionally from Peru and Colombia. It can be kept in a small school in a large aquarium.
Unlike Erythrinus and Hoplias these wolffish hunt in roving packs, cornering groups of smaller fish, especially characins, or chasing crustaceans and insects in the substrate or along the surface.
Their swimbladder is not as reduced as much as the other genera, so they are much more surface oriented and active than other wolffish. They can also do well in a community tank with other larger fishes such as catfishes, cichlids and larger characins, such as Myleus and Leporinus.
Hoplerythrinus will accept dry foods such as pellets, freeze-dried shrimp and insects, and sometimes even flake foods more readily than their relatives.
All wolffish are excellent jumpers and any aquarium must be covered at all times!
Hoplerythrinus also prefer flood zone habitats with mild or no currents and several hundred individuals can migrate deep into flooded plains or forests during the rainy season.
The other small species occasionally found in the hobby is Erythrinus erythrurus, often called the Redfin wolffish. Juveniles especially can show attractive red, yellow and even purple hatch marks on their flanks over an overall brown or burgundy body.
Margins of the unpaired fins can be bright red, yellow or white. The body shape is more stout than Hoplerythrinus and the swimbladder is reduced much further — to the point that the species swims in open water only when it wants to grab prey from the water column.
Erythrinus are more solitary, so groups require large aquariums with plenty of hiding places, allowing each fish to claim a territory. Short lengths of clay or PVC pipe make ideal caves for a relatively shy fish that may fight with conspecifics.
Fish that do not challenge them for territory and do not fit in their mouth are usually ignored.
Ideal tank mates are sturdy characins such as Myleus and Metynnis. Large-bodied cichlids such as Astronotus, Hoplarchus and Cichla also fare well.
Slow catfish risk having their eyes bitten when entering caves occupied by wolves.
Erythrinus will feed on live fish, crustaceans, worms and insects, and only slowly get used to frozen foods.
Erythrinus is found in swampy shoreline habitats and shallow clear or blackwater streams deep inside the forest. Besides insect larvae, all examined had Apistogramma, Moenkhausia and Nannostomus in their stomachs.
Most interesting are Hoplias. Usually only three species are exported for the hobby and most common is H. malabaricus, being widespread in both the Amazon and Orinoco lowlands and exported frequently from Peru.
Any wolffish bought in an aquarium shop will probably belong to this particular species.
Colour can range from mottled grey to brown and, depending on place of origin, almost black.
Juveniles are usually lighter and have bright yellow or green eyes.
In nature they are solitary, found in slow moving waters of virtually any habitat. The smaller the fish the shallower the habitat, and it’s not unusual to find finger-long H. malabaricus in less than 5cm/2” of water, stalking aquatic insects and small fish. As the fish mature they become less tolerant of each other and move to deeper water.
Adult H. malabaricus are not overly aggressive, but require a larger territory. Along riverbanks adults are usually spaced 3-4m/10-13’ apart.
As with all wolffish species, aquarium water chemistry is of little importance, as these fish can adapt to just about any common range of values.
Hoplias malabaricus are lazy, moving only when food is added to their environment. Juveniles will eat virtually any frozen or live food, but do well with frozen Mysis, smelt or cocktail shrimp.
They are often more active at dusk and dawn, so keep lighting subdued to allow them to show more activity during the day. Kept as a group of equal sizes they get along well until becoming sexually mature at 20cm/8”.
Minor injuries sustained in territorial fights usually heal quickly. Large wild Hoplias are often caught with severe injuries, missing eyes, deformed jaws and amputated pectoral or ventral fins, but seem otherwise normal.
As they mature, females develop a more robust shape and rounded stomach. They will become increasingly intolerant until a pair has formed, then will usually get along well and lay close together.
Breeding can usually be induced by first dropping the temperature, raising it to 28-29°C/82-84°F and slightly dropping the level of water.
During breeding the male digs shallow pits in which 2,000-10,000 yellowish eggs are laid in a cluster. He guards the nest and larvae until they hatch and spread out in the shallow water to hunt small prey.
In the aquarium the young will immediately eat Artemia nauplii and grow rapidly, eventually cannibalising each other.
The newest member of Hoplias is also the second most imported species. It was known as Hoplias sp. Black for many years and described as Hoplias curupira in 2009.
This fish will occur sympatrically with H. malabaricus, but usually occurs in a different niche.
The black wolffish prefers river banks of faster rivers, especially major tributaries of the middle Orinoco.
The body is more stout and less elegant than H. malabaricus and overall colour is a more uniform black or dark brown. The eyes are usually equally dark and less apparent. A maximum 30cm/12” size is considerably smaller than the 45cm/18” commonly reached by H. malabaricus.
The body is more stout and less elegant than H. malabaricus and overall colour is a more uniform black or dark brown. The eyes are usually equally dark and less apparent. A maximum 30cm/12” size is considerably smaller than the 45cm/18” commonly reached by H. malabaricus.
Black wolffish seem to prefer large shrimp and larger fishes. Stomach contents examined in the Orinoco region revealed Macrobranchium spp shrimp, juveniles of several cichlid species and larger sized Leporinus.
Hoplias curupira are more aggressive, both to each other and towards the keeper. It’s is not unusual to find one approaching the front glass with flaring gills or viciously attacking any object used to trap them.
Large wolffish can cause deep cuts to a keeper’s hands. Handle them with the same respect as a powerful reptile of equal size. Such extreme aggression also means the fishes can be fed directly with large tweezers and the fish quickly learn to take large cocktail shrimp or smelt from them.
H. curupira will try to swallow fish almost up to their own size and may attack larger fish. When keeping them in a community aquarium choose only robust tank mates of considerably larger size. Breeding behaviour is not known in the aquarium, but likely similar to other Hoplias species.
The fearless king
The most formidable Hoplias exported is the king of wolffish: the aimara, or trairão (Hoplias aimara and/or H. macrophthalmus). Juveniles and young adults sport a small black spot behind the gill cover.
It’s much larger and aggressive than the others and in nature is found in fast-flowing rivers and rapids where it preys on anything that moves. This species is absolutely fearless!
In the aquarium H. aimara is prized, but not easy to keep. Particularly large specimens will even hit the glass when the aquarium is approached, breaking their jaws, teeth, or glass itself. At over 30cm/12” they are difficult to keep — at over 100cm/40” they are best kept in acrylic tanks and left to experts.
Aimara have large and fearsome mouths and will attempt to swallow any other fish in the aquarium, including large loricariids, which their powerful jaws can break apart.
These monsters may also be kept together. If aquarium size allows, the animals are moderately territorial and will display to each other with flared gills and fins, but rarely bite each other. Pairs are formed at 50cm/20” and harmonise well together.
Nevertheless this species is best kept by experts who can handle the long-term requirements of these big fish. Unlike other wolffish H. aimara prefers fast moving water and can be more sensitive in bad water conditions. In low oxygen environment they become very intolerant of each other.
Moving adults can be dangerous because the fish will bite even out of the water and their 3cm/1.2” long teeth can penetrate most gloves and easily break plastic bags used in transport.
