I have a T. Squamosa (7-8 inches) that has been in my 50 gallon tank for at least the last 3 years. Over the last day the clam's exhalent siphon has appeared to have less color and a kole tang and midas blenny have been nipping at it( ex. siphon). The inhalent siphon appears more open than usual as well. Tank parameters are bassically unchanged (pH 8.0- 8.2, alk 9-11, salinity 1.024, temp 80-82). I did upgrade the lighting above that side from a 150 watt 6500k to 175 watt 10k about 3 weeks ago. The other side of the tank went from a 175 watt 10k to a 400 watt 10k but have slowly increased the photoperiod on that lamp. The clam did spawn about 1-2 months ago as well. Any thoughts/help would be appreciated I would sure hate to lose this guy.