Temperature preference behavior in Astyanax cavefishes

I noticed 2 papers that were given at AIM 2015 and 2017 on temperature preference behavior and its genetics.

Perhaps some of you should read an MS thesis from Texas Tech University from 50 years ago!

Johnson, Kenneth W. 1967. Temperature responses of the Mexican blind cave-fishes of the genus _Anoptichthys_. M.S. Thesis. Lubbock: Texas Technological Coll. 53 pp.

This was actually listed in my biblio at cavefin.org. Unfortunately it was not published in a journal.

Bob Mitchell (of Mitchell, Russell, and Elliott 1977) built a good temperature gradient lab apparatus that several of us grad students used back in the day. It is described in Johnson's thesis, which can be download from Texas Tech University's website of theses and dissertations at:

https://ttu-ir.tdl.org/ttu-ir/handle/2346/12680

It is a 7MB pdf.

I used the same apparatus in my MS thesis, published in 1973:

Elliott, William R., and R.W. Mitchell. 1973. Temperature preference responses of some aquatic, cave-adapted crustaceans from Central Texas and Northeastern Mexico. International Journal of Speleology, 5:171-189.

You can get that at my website, http://cavelife.info/ Look at the bottom of the home page at the link "Papers by Elliott et al." and there is a table of most of my publications with downloadable pdfs. You can also get our new book, "The Cave Fauna of California" there.

Below is my summary of K.W. Johnson's thesis:

Cheers,
William R. (Bill) Elliott
speodesmus@gmail.com

****************************
Johnson, Kenneth W. 1967.

The purpose of this research was to investigate the temperature responses of the cave-adapted fishes of the Genus Anoptichthys. The specific objectives of this study were: (1) to determine if there is a correlation between morphological regression and the ability to respond to an external stimulus; (2) to ascertain the possible significance of temperature discrimination as a mechanism for keeping troglobitic animals restricted within the cave environment. The epigean relative Astyanax fasciatus mexicanus was included in the study for comparative purposes.

Fishes were collected from:
1. La Cueva Chica, January and August, 1966, and March 1967, 23.0, 24.5, and 24.5°C respectively.
2. Sótano de la Tinaja, January and August, 1966. 22.0 and 23.0.
3. Sótano del Arroyo, two collections were made in August of 1966, 21.0°.
4. Cueva de El Pachón, two collections were made in January, 1966, and August, 1967, both at 25.5°.
5. The Astyanax fasciatus mexicanus used in the study were collected from two large pools near kilometer-post 481 [near Los Sabinos], which is in the vicinity of the A. hubbsi caves.

The construction of the gradient chamber used in this study may be seen in Figure 6 . The aluminum channel was constructed of 1/2 inch aluminum…

In the experimental gradient, all of these species exhibited a distinct response. Contingency table analysis between the experimental and control data from each sample revealed highly significant differ ences (P< .001). Comparisons of interspecific experimental data also revealed significant differences . However , the interspecific control data also differed significantly making the experimental comparisons invalid, except between A. jordani [Chica] and A. antrobius [Sabinos].

Conclusions:
The conclusions that can be made from the data gathered in this study are as follows:
1 . The fishes of the genus Anoptichthys and their epigean relative Astyanax fasciatus mexicanus have a distinct discriminatory ability in a temperature gr adient chamber.
2 . Contingency table analysis shows the responses to a temperature gradient of all three species of Anoptichthys and Astyanax fasciatus mexicanus to be significantly different. These comparisons are valid only between A. antrobius [Pachón] and A. jordani [Chica], however.
3. The thermal preferendum of the three species of Anoptichthys and the river fish Astyanax fasciatus mexicanus is 23 to 30°C.
4. Of the three species of Anoptichthys, the most regressed form, A. antrobius, is the most temperature specific . There is a significant difference between the frequencies of the occurrences of this species and A. jordani within the thermal preferendum.
5. Anoptichthys jordani , the least regressed form, is the least temperature specific species of the genus. There is also a significant difference between the frequencies of occurrences of this species and the Arroyo population of A. hubbsi within the thermal preferendum.
6 . The river fish Astyanax fasciatus mexicanus is less temperature specific than the fishes of the Genus Anoptiohthys.
7. None of these four species are particularly stenothermal.
Sign In or Register to comment.