|Three filamentous cyanobacteria from a freshwater aquarium. Identified by an amateur at the genus level as; Lyngbya (thick filaments), Jaaginema (sinuous filaments), and Romaria (short filaments).|
Q1. Are the filaments 3 micrometers wide or more? A-Yes. Q2. Are the filaments cylindrical, long, sometimes constricted at the cross walls, but cells not barrel shaped or sub-spherical? A-Yes. Q3. Are the cells short, always shorter than one half the cell width? A-Yes. Then we come to the crunch. Q4. Are the filaments in vegetative state always without sheaths (if present formed only under stress)? Sheaths again! The problem is that the species 2 sample I examined in Chapter XVI which showed clear evidence of sheaths, could have been stressed because it had sat around for a week. So I examined a fresh sample.
|Filamentous and unicellular cyanobacteria from a freshwater aquarium.|
|Fragmented sample of filamentous cyanobacteria from a freshwater aquarium.|
|Diatoms alongside unicellular and fragmented filamentous cyanobactera from a freshwater aquarium.|
|Fresh cyanobacteria sample from a freshwater aquarium showing evidence of sheaths. Possibly Lyngbya.|
|Possible Lyngbya filaments showing evidence of sheaths.|
Finally species 3. Q1. Are the trichomes less that 3 microns wide? A-Yes. Q2. Are the trichomes without sheaths or within simple, thin sheaths (when present always one trich/sheath) solitary or in mats, trichomes isopolar (both poles with same morphology)? A-Yes. Q3. Are the trichomes without sheaths, but may possess wide or diffuse mucilaginous envelopes? A-Yes. Q4. Are the trichomes straight, wavy, or irregularly coiled? A-Yes. Q5. Are trichomes mainly short, curved or irregularly coiled, usually only few celled, disintegrating , sometimes enveloped by an indistinct wide mucilaginous envelope, neighbouring cells occasionally disorganised? A-Yes (I guess) = Romaria. I can't find any photos of Romaria so I think I'm on shaky ground with this one. Correct me if I'm wrong.