The below is a close up view of the area, detailing the different tribuaries leading to the lake as forwarded to me by Max.
The Base Colour:
Almost all Bukit Merah crossbacks are blue in base colour. The base colours range from dark blue,blue,light blue and almost silver colour. They will retain the base colour until the size of 10”-12” by then the gold frame might cover the base colour depending on the frame thickness.Some will be totally covered by the gold colouration and become Gold Base x-backs. There are also crossbacks of other base colours eg purple and green but these are few and rare
Alor Pongsu CrossBack.
The frame thickness can range from thin to thick. They will have a high chance of retaining the permanent blue base.The head are slight spoon with medium length body shape and fairly large finages.
Cangkat Lobak River CrossBack.
The frame thickness can range from thin to thick..The head are slightly spoon with medium length body shape and very small finages.The x-back in this region can grow to medium size
Gedong River CrossBack.
The frame thickness are thin.All will retain blue base when fully grown.The head are flat and long with long body shape.Finages are medium size.
Kerian River CrossBack.
The frame thickness can range from thin,thick to no frame (gold base).The head are rounded (bullet head) with long body shape and small finages.
Bukit Merah Lake CrossBack.
The frame thickness are very thick.Most will become gold base when fully grown.The head are rounded and short with short body shape and very small finages.The x-back in this region are small size ( up to 28” in length).