If a male shark has 40 chromosomes in each of its sex cells, what is its diploid chromosome number?

If north is straight up in the map, then the blue stream is flowing from NW to SE or upper left to lower right. I know the flow direction because the elevations of the stream bed go from 1000-600 to the lower right. There is a steep hill on the SW side going from 900 elevation at the stream valley to 1500 at the peak and I know it is steep because the contours above the stream are close together. On the NE side is a hill with a relatively gentle slope going from 800 to 1300 elevations and with fairly widely spaced contours which indicate the gentler slope.