194
WILLIAM MACNAE
Older nests containing larvae have been described by Harms (1929,
1935) and Eggert (1935). These older nests are saucer-like with raised
rims so they must have been those of P. chrysospilos or P. schlosseri.
The nests of the large Periophthalnzodon schlosseri were described by
Harms (1929) as saucer-like or bowl-shaped little ponds up to 1 m
across. They are also described and illustrated by Verwey (1830). I
have come across such bowls (nests) (Fig. 63) a t any level of the mangal
except the landward fringe, but they are commonest on sloping banks
just below the mangrove line along creeks or just within the seaward
avicerinia fringe. The formation of the pellets making the raised edges
to the nest suggest that the method of making them is similar if not
identical with that described above and uscd by Yeriophthalmus
chrysospilos.
Boleophthalmus and Scartelaos both show vigorous display patterns
the mcaning of which is not completely clear. The displays of Boleophthnlrnxs are the more confusing because i t does not appear to be possible
to sex individuals in the field. A common display incident, seen while
watching Boleophthalmus, is a confrontation with two individuals in a
straight line (Fig. 68), open mouth to open mouth and pushing one
another strongly in a fashion analogous to stags pushing antler to
antler. The inside of the mouth of Boleophthalmus is a dark indigo
blue, presumably of some significance in display. This species too, like
FIG. 68. Boleophthalrnus hodduerti (size en. 15 cm). Confrontation, note thp open mouth
and then the two fish pushing one another, open mouth to open mouth. (From
photographs by I. Polunin.)
WILLIAM MACNAE
Older nests containing larvae have been described by Harms (1929,
1935) and Eggert (1935). These older nests are saucer-like with raised
rims so they must have been those of P. chrysospilos or P. schlosseri.
The nests of the large Periophthalnzodon schlosseri were described by
Harms (1929) as saucer-like or bowl-shaped little ponds up to 1 m
across. They are also described and illustrated by Verwey (1830). I
have come across such bowls (nests) (Fig. 63) a t any level of the mangal
except the landward fringe, but they are commonest on sloping banks
just below the mangrove line along creeks or just within the seaward
avicerinia fringe. The formation of the pellets making the raised edges
to the nest suggest that the method of making them is similar if not
identical with that described above and uscd by Yeriophthalmus
chrysospilos.
Boleophthalmus and Scartelaos both show vigorous display patterns
the mcaning of which is not completely clear. The displays of Boleophthnlrnxs are the more confusing because i t does not appear to be possible
to sex individuals in the field. A common display incident, seen while
watching Boleophthalmus, is a confrontation with two individuals in a
straight line (Fig. 68), open mouth to open mouth and pushing one
another strongly in a fashion analogous to stags pushing antler to
antler. The inside of the mouth of Boleophthalmus is a dark indigo
blue, presumably of some significance in display. This species too, like
FIG. 68. Boleophthalrnus hodduerti (size en. 15 cm). Confrontation, note thp open mouth
and then the two fish pushing one another, open mouth to open mouth. (From
photographs by I. Polunin.)