鉴于我们最近在给定复合物中挑选神秘物种的趋势，就像我们为pseudanthias pascalusandNemateleotris helfrichi, we continue yet again with a rather massive undertaking. This time with假牙齿腹腔。这个美丽的物种在大洋洲的大部分地区都广泛，但似乎很容易与至少三个主要且相当不同的表示，可以根据颜色和地理范围进行分组。其形式的流动性表明其对物种形成的敏感性，夏威夷的一个孤立的民众已经授予了完全的分类升级。这是夏威夷假人。
当然，重要的是要注意，无论如何，本文都不是分裂物种的科学标准，而是基于对复合体内各种形式的比较和分析的暗示性文章。在上面的范围图中P. ventralisyou can see that it has been roughly divided into a cross section of four, with major distinctive groups being found in four quadrants. These are the Southern Pacific and French Polynesian island chains, the Australian region encompassing New Caledonia and the Coral Sea, the Marshall Islands and Japan with Mariana as an intermediate, and finally Hawaii; where speciation has already awarded the area with the endemic夏威夷P.。
库克群岛，南太平洋，法尼西亚和皮特凯恩群岛
The type locality of假牙齿腹腔is Gannet Ridge, off the Pitcairn Islands. For that reason, the forms here and the surrounding locales should by right depict the actual representation of the species. We’ll explore these, as well as the other forms in a clockwise manner based on the quadrants of the map above and try to pick out any phenotypic or morphological differences amongst the various forms.
The collage above depicts various specimens from the first quadrant of the Southern Pacific and French Polynesian range. In this it also includes the Cook Islands and the Pitcairn island groups. Seeing as the type locality for the species originates from here, these should be considered the benchmark type and all other regional forms following should be compared carefully with these.
在P. ventralis,男性是钢铁般的紫色整体的头脑d encapsulated in yellow. The dorsum just beneath the dorsal fin is yellow washed, but is peppered so heavily in purple spots that in some extreme cases, the underlying yellow is obliterated completely. These purple spots tend to remain circular and distinct, which is an important characteristic when comparing with specimens in other locales. The dorsal fin is red only on the anterior spiny portion (clear in dead, preserved specimens), and hyaline or yellow tinted on the soft portion. The leading edge of the soft dorsal fin is also unmarked with no purple lines. Caudal fin is largely clear and unmarked, except for a pair of vertical purple lines. The anal fin is clear, but has a strong purple line delimiting a more deeply colored region corresponding to the anal spines and first rays which form the elongate leading edge of the fin.
The females share the same steely purple ground coloration, but are unmarked except for a yellow dorsal fin which creeps to a sliver of the dorsum before ending obliquely at the caudal peduncle. A red arching stripe separates the two colours near the posterior portion of the dorsum. Females lack secondary coloration such as the purple spotting that the males possess.
Coral Sea, Vanuatu and New Caledonia
Moving west to the Coral Sea and New Caledonian region including Vanuatu, we find a completely different looking regional form ofP. ventralis。这里的雄性主要在背鳍和尾巴上有所不同，并且在背鳍下方的身体沿着身体具有更严格的斑点图案。女性在很大程度上与类型物种中的雌性相似。我们将仔细观察，并更清楚地确定下面的差异。
在this region, the males are also steely purple in basal colour, with the head encapsulated in yellow. The dorsum is also yellow washed, but contains a series of super imposed purple spots that conjoin to form a reticulated pattern travelling horizontally. In addition to that, a secondary set of yellow blotches and squiggles sit just beneath the purple reticulations. There are therefore two sets of body coloration here; a series of purple reticulated spotting on the yellow base of the dorsum, and a second set of yellow squiggles on the purple body coloration just beneath. The yellow squiggles is prominent enough such that it gives an impression of a separate line coming out of the head region and starting just behind the operculum.
The dorsal fin takes on the reverse coloration as the type species, with the anterior spinuous portion coloured in yellow while the soft rays in red. The red coloration in the soft rays is only limited however to the anterodorsal region, and does not creep to the posteroventral base, where it is coloured yellow. This is delineated by a diagonal line originating from the purple spotting on the dorsum, which extends to the tip of the fin.
The caudal fin also differs by having a weak red blotch or bar near the edge, with purple lines along its margin which always fails to encircle it. Like the type species, the anal fins are clear, but has a strong purple line delimiting a more deeply colored region corresponding to the anal spines and first rays which form the elongate leading edge of the fin.
Females are nearly identical to the type species with the same yellow dorsal fin and red arching stripe separating the two colours near the caudal peduncle.
Vanuatuan标本的外观与珊瑚海样相同，在上面的照片中，可以更清楚地看到背鳍上的紫色线条。红色前区域由背鳍的黄色后底底清楚地分离，这条紫色线可能源于体内的紫色斑点，也可能不是源自体内的紫色。但是，这条线总是以这种区域形式出现。
The photo above also more clearly demonstrates the purple spotting that can be seen here joining up into an irregular chain or reticulated pattern, very unlike the individual spots that pepper the type species in the Southern Pacific and French Polynesia. The secondary yellow squiggle that sits just beneath can also be observed.
新的喀里多尼亚形式基本上与珊瑚海和瓦努阿旺地区的形式相同。看到它们都位于同一生物地理区域内，因此变化不太可能令人震惊。然而，新的Caldonian形式似乎确实更加呈淡淡和更丰富的色彩，但是未知该特征是来自鱼本身还是拍摄照片中的相机设置。
The reticulated patterns on the dorsum do however appear to spread a little more extensively ventrally, but overall they do bear the same characteristics as the Coral Sea and Vanuatuan forms. The tail is also weakly spotted in red and the purple lines always fail to encircle it.
Japan, Marianas and the Marshall Islands
Moving northwards from the Coral Sea, Vanuatu and New Caledonian region, a different complex ofP. ventraliscan be found. This quadrant comprise of individuals found in the Marshall and Mariana islands as well as Japan, where the species is at the western most limit of its range. The forms here are more variable than those in the preceding locales, and show a wide range of intermediates especially in the pattern on the caudal fin.
The basal coloration of the males are as usual, steely purple with the head encapsulated in yellow. The dorsum is yellow washed as usual, and the purple spotting here are numerous, but small and never joined like the New Caledonian and Coral Sea forms. The specimens from this geographical area also lack the development of the secondary yellow squiggles found below the dorsum, and even if, it is usually highly vestigial and under developed.
Dorsal fin is entirely orange or red sans the posterior soft portion which is always yellow. In this complex, there is an absence of a diagonal purple line delimiting the two colours on the fin. The most distinctive feature for this group is the highly developed red spotting on the caudal fin, which is present in all male specimens. In many cases the caudal blotch is almost fully circular, with varying completeness of encirclement from the bordering purple lines. In fact, it is not unusual to find specimens with a well developed caudal spot fully circumscribed by the bordering purple lines. Another distinctive feature for this group is the lack of any delimiting lines on the anal fin, being completely yellow.
The males from this region have by far the most under developed dorsum markings, lacking the intricate reticulations that the other forms possess. They however are very unique in the caudal and anal fin characteristics, which is very much different from the other forms. The three photo collages from Ogasawara, Saipan and the Marshall Islands show some variability amongst individuals, especially in the development of the caudal blotch.
However the specimens are consistent enough to warrant placement in the same biogeographical range, possibly belonging in the same complex.
The females from this region are also different, and lack the distinctive red arching stripe that separates the yellow dorsum from the purple body. In most individuals, the stripe is entirely absent, or if rarely, found only as a thread.
菲律宾, Fiji and Palau (?)
在our search, we’ve been unable to find any information or photos pertaining to this species’ existence in Fiji and Palau. Fiji sits in the middle of the Coral Sea and the Cook Islands, so it is not unlikely that the species can be found there as well. However if the absence ofP. ventralis在斐济确实是肯定的,那么它作为说junct range between the Coral Sea individuals and those of the Cooks. This isolation could further support the speciation of the Coral Sea and New Caledonian forms.
Its absence from Palau is also curious, being one of the Oceanic islands situated so close to Saipan and the Marshalls. Perhaps the lack of photos and information is due to it being exceedingly rare in the area, or perhaps it is totally absent there. Why or whether or not this is true, we are not sure.
P. ventraliscan also be quite dubiously found in the Northern Philippines, where again it appears to be very rare. We’ve only managed to find a single photo of an aquarium specimen that arrived from a Philippine import. Being so close Japan, it is not unlikely thatP. ventraliscan be found there. The supposed Philippines individual above shares the same overall characteristics as the Japanese forms, and if anything it probably belongs in the same complex.
Hawaii and Johnston Atoll
夏威夷和约翰斯顿群岛是多种特有物种的家园，其中一种是以前孤立的形式假牙齿腹腔现在已经实现了完全的分类升级。鱼，曾经被认为是P. ventralis, is now recognised as夏威夷假人。夏威夷P.differs markedly fromP. ventralis, with the basal coloration drifting away from the usual purple, to take on a rich burnt orange. The posterior third of the body fading toward the caudal peduncle is a light lilac. The purple spotting that is so characteristic ofP. ventralisis reduced to a mere fraction in the males, and in some cases totally absent.
在terestingly,夏威夷P.also differs morphologically, being much larger and with extremely long ventral fins; much longer than its sister species. These can often reach well pass the anal fins. The females, pictured below, is uniformly yellow, but in some individuals and perhaps under different lighting, the usual purple ventral portion of the body can be seen. Other than that, it is very much distinctive and different from the usual females ofP. ventralis。
Table of comparison
Although this article is derivative and observational, but based on distribution as well as color variation, it is not unlikely that假牙齿腹腔houses more than one species in its complex. The Coral Sea and New Caledonian specimens seem highly likely to form a distinctive sister group, and more studies or examination should be done on those specimens.
在出现流动性ance goes, it seems that the males differ rather greatly from area to area, while the females remain relatively similar. The exception being those found in Japan, Marianas and the Marshall Is, where the females lack the red arching stripe that separates the yellow dorsum from its purple body. Males differ primarily in their dorsal and caudal fin markings, as well as the intensity and arrangement of the purple spotting on the dorum. In the New Caledonian and Coral Sea specimens, the spotting is not only highly conjoined and reticulated, but an additional set of yellow squiggles are present just beneath.
夏威夷P.is a classic and very good example of allopatric speciation, where a new and totally distinct species has evolved away from the original lineage. It is entirely possible that some of theseP. ventralisforms we’ve discussed today have begun speciating away from the original type, and further analysis may one day warrant the elevation of these variants to full species level.
A big thank you to Joe Rowlett, who has been highly instrumental in the crafting of this article. The distribution maps as well as the coherence of this piece should be credited to him as well.
