Chances are you will probably have a difficult time distinguishing those at the species level by simple morphological characteristics. I would suggest taking the molecular route and see if there is a little more difinitive way to speciate (sequencing, RFLP's, etc.)

Hi Swapna,

A careful observation of these pictures reveals that these might b two different species of Rhizopus. In Rhizopus sp. 1 the production of sporangiophore is directly from stolon where as in Rhizopus sp. 2 whorls of sporangiophores located terminally on rhizoids. Some other feature in these photographs is the length, color and texture of sporangiophore besides the details on sporangium structure including the apophysis and their dehiscence. A comparison of these characters is not possible as in current form pictures are lacking information such as magnification, scale and type of microscopy used. Apart from these observations, a host of other characteristics are needed, including temperature treatment for confirming the species identification of fungus in question? However, with these limited information it appears that Rhizopus sp. 1 may be R. oryzae and Rhizopus sp. 2 can be R. stolonifer.

Better go for molecular analysis which will give the difference among isolates

Plz send me the microphotograph of the sp.

suggest you consider the macroscopic description, the culture conditions.

  On the other hand in the microscopic description is important sporangioforo size, shape, size and color of the spore in KOH 10%, stolons and rhizoids. Finally the DNA analysis you will resolve the question.

Step 1. Search literature, just in case your species dont find a match then

Step 2. go for ITS sequencing

Dimensions are important tools to identify a specie. Secondly, the habitat also helps in identification.