What type of seahorse is this?

Dear hobbyist:

Unfortunately, the photo of the seahorse you are wondering about did not come through with your post and I have not been able to examine the picture yet in order to offer an opinion.

If you want to try posting the photograph on this forum again, this is how to proceed:

First you have to host the photographs(s) you would like to post somewhere like photobucket or AOLmyspace, but you must make it small as the board will only take a small photo.

Next go-ahead and type the text of your message as usual, and then, when the message is ready, place your cursor exactly where you would like they image of the photograph to appear in the message. Then click on the orange Img tag in the reply window. The following block of text will appear where you had placed the cursor:

[img size=150][/img]

Now all you have to do is add the address of the hosted picture directly behind the final bracket in the block of text above. For Photobucket, just place your cursor on the photograph you want to use, and a drop-down menu will appear — go to "Copy IMG" at the bottom of the drop-down menu and it will automatically copy the address of your picture. All you have to do is to go back to your post, place the cursor of the mouse directly behind the final bracket in the block of text I pointed out above, and paste the photo book address for your image right there.

Then just make sure they hit the "close all tags" tab just above your message, and submit your post as usual.

Or, if you prefer, you can insert the photograph in an e-mail and send it to me off list ([email protected]). Either way, as soon as I received picture, I will examine it closely and try my best to determine what species of seahorse it is and whether or not the individual and the photograph is a female.

In order to make an exact identification of a seahorse, you need to key out the seahorse using its meristic counts (i.e., number of rings and fin rays) and it’s morphometric characteristics (i.e., snout length, coronet, spinal development, etc.). Unfortunately, it is very difficult to accurately count the trunk rings and tail rings on a seahorse from a photograph, and all but impossible to count the number of fin rays in its dorsal and pectoral fins.

But that’s usually not necessary in order to distinguish Hippocampus reidi seahorses from Hippocampus erectus seahorses. It is often possible to tell those two species apart by their coloration. For example, the lined seahorse (H. erectus) often has a distinctive pinstriped color pattern that sets it apart, whereas H. reidi seahorses often have fairly large dark spots on their body. Hippocampus erectus does not have such dark spots; when spots are present on H erectus, they are small white or silvery spots, not large dark dots…

In addition to the meristic counts and morphometrics taxonomists use to distinguish between species, there are certain other key features that are important to consider and easier to apply. For example, the seahorse’s coronet or “crown” is an important identification feature. It consists of a bony projection extending from the top of the seahorse’s head. The size and shape of the coronet are species dependent. It can be low and rounded or tall and elaborate, sometimes exaggerated to ridiculous proportions as in the Japanese species Hippocampus coronatus, in which the coronet may be taller than its head is long. In some seahorses it is almost nonexistent, nothing more than a smooth bony ridge (e.g., Hippocampus capensis and H. fuscus) and in others it is high and prickly, adorned with several distinct tines that give it a crownlike appearance (H. barbouri or H. procerus). Not only are the height and thickness of the coronet and the number of tines or projections on the crown important characters for distinguishing between species, the size and shape of the coronet may also be used to identify individual specimens, for it is said that no two coronets are exactly alike in all their details. Endless variations in the size and shape of the coronet are thought to make this feature as distinctive as human fingerprints. The size and shape of the coronet can be useful when identifying genuine Hippocampus kuda seahorses

In H. kuda, the rounded coronet is typically low to medium in height, but often overhangs at the back, and frequently has a cup-like depression in the top; sometimes with broad flanges. You may be able to identify kuda seahorses from H. reidi or H. erectus depending on whether or not the coronet overhangs at the back.

However, it is often particularly vexing to try to identify purported Hippocampus kuda seahorses because a whole constellation of different stallions have been described as H. kuda at one time or another. Indeed, the designations kuda and histrix are known to encompass entire complexes of seahorses that no doubt include a number of valid species aside from their namesakes. (At one time, every large smooth-bodied seahorse from the Indo-Pacific was automatically branded Hippocampus kuda, while virtually every spiny seahorse from the Indo-Pacific was apt to be labeled Hippocampus histrix.) Dr. Amanda Vincent has examined the type specimen for Hippocampus kuda and she has told me that the overwhelming majority of seahorses offered in the aquarium trade as H. kuda are most certainly nothing of the sort. So short of doing a DNA analysis, the most definitive statement we can make regarding such seahorses is that they probably belong to the kuda complex; breaking it down any further than that becomes increasingly problematic, and it’s really impossible to say even that much based only on a photograph…

But for whatever it’s worth, here are the meristic counts and distinguishing characteristics for the genuine Hippocampus kuda:

Meristic Counts:.

Rings: 11 trunk rings + 36 tail rings (tail rings vary from 34-38).

Dorsal fin rays: 17-18 soft rays spanning 2 trunk rings + 1 tail ring.

Pectoral fin rays: 16 soft rays (rays vary from 15-18).

Morphometrics:

Snout length: 2.3 (2.0-2.6) in head length.

Other distinctive characters:

Coronet: low-medium, rounded, overhanging at the back, often with a cup-like depression in the top; sometimes with broad flanges; not spiny.

Spines: low, rounded bumps only; this is a smooth-bodied seahorse with conspicuous trunk rings.

Key Features: deep head; deep body; thick snout.

Adult height: 3-12 inches (7-30cm).

Color and Pattern:

The true Oceanic seahorse (Hippocampus kuda) has two main color phases: black and yellow. Specimens are often totally black with a grainy texture; otherwise they are pale yellow or cream with fairly large, dark spots (especially in the females) and a black line running from their chest to their abdomen. It is the latter color phase that is responsible for their common names of Golden or Yellow Seahorse and the Spotted Seahorse. The golden yellow specimens darken in response to stress and thus often appear very dark or olive green when first received, only brightening up and resuming their true coloration once they are at home in the aquarium.

True kuda tend to be sexually dimorphic in coloration. Adult females are typically yellow with large dark spots about 2-4 mm in diameter (Mai 2004a). Wolfgang Mai maintains a breeding colony of H. kuda and never observes yellow males with black spots (Mai 2004a). Males often exhibit a grayish-black background coloration with numerous pale lines, overlaid with a pattern of black dots.

Other variable color forms are less common, but some individuals may be cryptically colored or sandy to blending in with their surroundings and some specimens show a mixture of black and yellow.

Let us see a photograph of the seahorse you are trying to identify, and we would be happy to help you in that regard.

Respectfully,
Pete Giwojna