Why? A. "Ordinarily, a smaller, shallower body of water would be more likely to freeze than a larger, deeper one," said Jeff Warner, a meteorologist at Penn State, "but other factors are currently at work".
Thus, crater lake fish reared in lab conditions maintain shallower body shapes than those of wild fish captured in the great lakes.
Interestingly, it was those tadpoles with the shallower body-shape induced by the stressful environment (decreasing water levels) that had the best swimming performance, which illustrates the decoupling of locomotor performance between the tadpole and froglet stages.
In contrast, guppies with low consumption rates had shallower bodies, more downturned mouths, and longer, less tapered caudal peduncles.
The relationship is presented graphically in Fig. 3: tadpoles that performed better in terms of swimming speed and acceleration had shallower bodies but higher tail muscles.
Currently, we have no adaptive explanation for this, but it has previously been reported that animals that undergo accelerated development, usually have shallower bodies [7].
A separate test of water level treatment with swimming performance removed from the model showed that tadpoles from the simulated pool drying treatment significantly differed in shape (t1,59 = 2.56, P = 0.013) from those from the permanent water, in that they had shallower bodies (Fig. 3).
Paria males also had more negative values for PC2, corresponding to shallower bodies (Fig. 3).
For example, some transgenic fishes modified for faster growth have been shown to have altered opercula and caudal peduncles, deeper heads and shallower bodies than nontransgenic fishes (Farrell et al. 1997; Ostenfeld et al. 1998; Li et al. 2009).
Our results fit this paradigm in that oil-polluted and not-polluted guppy populations showed morphological differences that are at least partially parallel between watersheds (Figs 5, Fig S6): guppies from oil-polluted sites have shallower bodies and (especially) deeper and larger heads than do guppies from not-polluted sites (Fig. 4).
It's a shallow, body of water about a mile long and a half-mile wide.
