Is there an explicit way of
classifying (with regard to their compatibiliy with $\Omega_+$ or $\Omega_-,$ see below)
the various families of
equivariant holomorphic embeddings from $\mathbb{CP}^1$ to the quintic $Q$, such that $f_*[\mathbb{CP}^1]=2 \in H_2(Q,L;\mathbb{Z})?$

I'd like to know a phenomenology of what one can find, e.g., that only two or three kind of maps would have to be considered, for example the ones giving rise to an open surface, or to an unoriented surface with a crosscap.

Take a *general* quintic
(for which I don't know a concrete example to write down its equations),
the antiholomorphic involution
$$\sigma: \mathbb{CP}^4 \ni (x_1:x_2:x_3:x_4:x_5) \mapsto (\overline{x}_2:\overline{x}_1:\overline{x}_4:\overline{x}_3:\overline{x}_5),$$
$L$ the fixed locus of $Q$ under $\sigma,$
and $\Omega_\pm: \mathbb{CP}^1 \to \mathbb{CP}^1 \ (u:v) \mapsto (\overline{v}:\pm\overline{u});$
equivariance means $f\circ\Omega=\sigma\circ f.$

This should be possible in accordance to Clemens conjecture with $d=2,$ which is proved for small $d$ by
[Katz][1] (see also [Katz2][2]):
for a *general* quintic, we expect from [Klemm][3] $n^{g=0}_{d=2}=609250;$ it is known that Fermat quintic is not general in the sense of Clemens conjecture, since we have continuous families of maps.

Here $d$ can be thought more or less equivalently either as the homogeneous degree of the map or as the class in $H_2(Q;\mathbb{Z}).$

  [1]: http://www.numdam.org/numdam-bin/item?id=CM_1986__60_2_151_0
  [2]: http://arxiv.org/abs/alg-geom/9312009
  [3]: http://arxiv.org/abs/hep-th/0612125