Diagnoses
- The iridescent colours on the male tend to be bluer. Front view of a male is white in colour.
- Iridescent colours on a female are greener. Front view of a female is black or dark brown in colour.
Note however, that colour description provided only aids in the brief identification of T. bhamoensis in the field. Colour is not reliable characteristic as iridescence can fade over time, especially when it is captured and preserved in alcohol. For better spider identification, genitalia morphology should be observed and compared to species drawings or photography under laboratory conditions.
|
Fig. 5a. Dorsal view (top) and frontal view (bottom) of T. bhamoensis male. (Photo: Vijay Anand Ismave.I)
|
Fig. 5b. Dorsal view (top) and frontal view (bottom) of T. bhamoensis female.
(Photo: Vijay Anand Ismave.I)
|
Basic Anatomy
Fig. 6. shows the basic naming of anatomical features of a spider. Structure of each feature can differ from the picture.
An interesting fact about spiders: They have the ability to regenerate lost limbs!
Bad news for spiders: The ability to regenerate limbs is dependent on when the limb is lost.
The intermoult period is known as the time between moults. A spider's appendages have the ability to be regenerated if it is lost in the first 25% of its intermoult period. The spider is then able to regenerate their limb slowly through successive moults. However if the limb is lost close to the timing of its next moult, the spider cannot regenerate it (Ramel, 2013).
|
| Fig. 6. Basic anatomical features of a spider. (Photo: Gordon Ramel) |
|
Optical Anatomy
T. bhamoensis, like most salticids, have four pairs of eyes, with the Anterior Median Eye (AME) (Fig. 7.) being the largest of all four pairs. It is usually referred to as the primary eyes as they detect objects directly in front of the spider. The other three pairs of eyes are known as secondary eyes and aids vision under dim light conditions as well as warn the spider of movements within its periphery.
The eyes of salticids has a curved cornea and a lens that has a fixed focal distance. The structure of the AME is also tapered instead of spherical (Atkinson, 2009). This produces a very narrow scope of vision for T. bhamoensis. However, salticid eyes also has a cup-like front to the receptor cell mass and vitreous material filling the depression, serving as a secondary lens that gives the AME its telephoto capacity (Atkinson, 2009). This is why jumping spiders are indeed harder to catch than most other spiders. They can distinguish objects that are 30-40 cm away from its secondary eyes, and see it with its AME once it is within 20 cm distance! (Ramel, 2013)
Salticids are also known to be sensitive to four wavelengths of light: 360 (Ultraviolet), 480 (Blue), 500 (Green), 580 (Yellow) nm (Ramel, 2013).
|
| Fig. 7. Basic anatomical features of a salticid eye. (Photo: Ron Atkinson) |
|
Internal Anatomy of T. bhamoensis
|
|
|
Sexual organs
'Immature' spiders are known as juveniles and they do not have any noticeable sexual organs to distinguish them from a male or female. Only after several moults until maturity, do their sexual organs develop.
Fig. 8a and b shows the genitalia of the male T. bhamoensis located at its palps, in contrast with the female's genitalia located on the ventral side of the abdomen (Fig. 8c and d).
By observing the morphological features of a matured male and female T.bhamoensis, the male will tend to have more swollen palps than females. This feature is better observed under a stereo-microscope. Matured females will have a very visible epigyne instead of swollen palps. An important thing to note when looking out for the female's epigyne under the stereo-microscope: do not mistake the book lungs for the epigyne!
Refer to Fig. 6 to differentiate the position and relative size of the book lungs and epigyne in a spider.
|
| Fig. 8a. Thiania bhamoensis - ♂ - Bali - palpus, ventral view- © (Proszynski, J., Deeleman-Reinhold, C. L., 2010) |
| Fig. 8b. Thiania bhamoensis - ♂ - Bali - palpus, lateral view- © (Proszynski, J., Deeleman-Reinhold, C. L., 2010) |
|
| Fig. 8c. Thiania bhamoensis - ♀ - Bali - epigyne- © (Proszynski, J., Deeleman-Reinhold, C. L., 2010) |
| Fig. 8d. Thiania bhamoensis - ♀ - Bali - epigyne, internal structure- © (Proszynski, J., Deeleman-Reinhold, C. L., 2010) |
|