to the 2D suspension of disk-like squirmers [@PRE_Ricard], where hydrodynamics suppressed phase separation.

Inspired by the self-assembly observed in experiments with either bacteria [@PRL_bacteriaFastest] or active colloids [@Cecille] and by numerical works on 2D dilute suspensions of active brownian particles (ABP) interacting via isotropic short-range attractions [@SoftMatter_26; @SoftMatter_27; @SoftMatter_28; @SoftMatter_43], we have studied a semi-diluted quasi 2D suspensions of attractive squirmers [@SoftMatter17], to unravel the role played by hydrodynamics in suspensions of attractive active particles.

[Most of the nowadays synthetic active colloids are colloids partially coated with Pt. These colloids self-propell by a catalytic reaction of H$_2$O$_2$ and O$_2$ taking place at the Pt surface. This mechanism of colloid’s propulsion is due to phoresis. On the one side, properly modeling the phoretic interactions can be quite complicated [@phoretic39; @phoretic40; @phoretic41; @phoretic42; @phoretic43; @phoretic44], eventhough there are experiments, simulations and theories that consider them relevant for particles’ propulsion. On the other side, which interactions dominate in these systems are still a matter of debate [@JCP_Benno2019].]{}

[From the experimental point of view, several studies have focused on understanding the effect of hydrophobicity in catalytic Janus colloids. Modifying the surface of the particles, the authors of Ref. [@Manjare_HydrophobicJanus] found that particles with an 