Different species can now have different minimum levels of air

code/modules/mob/living/carbon/human/life.dm

@@ -359,7 +359,7 @@
 
 		return 0
 
-	var/safe_pressure_min = 16 // Minimum safe partial pressure of breathable gas in kPa
+	var/safe_pressure_min = species.minimum_breath_pressure // Minimum safe partial pressure of breathable gas in kPa
 
 
 	// Lung damage increases the minimum safe pressure.

code/modules/mob/living/carbon/human/species/species.dm

@@ -104,8 +104,8 @@
 	var/warning_low_pressure = WARNING_LOW_PRESSURE   // Low pressure warning.
 	var/hazard_low_pressure = HAZARD_LOW_PRESSURE     // Dangerously low pressure.
 	var/light_dam                                     // If set, mob will be damaged in light over this value and heal in light below its negative.
-	var/body_temperature = 310.15	                  // Species will try to stabilize at this temperature.
-	                                                  // (also affects temperature processing)
+	var/body_temperature = 310.15	                  // Species will try to stabilize at this temperature. (also affects temperature processing)
+	var/minimum_breath_pressure = 16				  // Minimum required pressure for breath, in kPa
 
 	var/heat_discomfort_level = 315                   // Aesthetic messages about feeling warm.
 	var/cold_discomfort_level = 285                   // Aesthetic messages about feeling chilly.

code/modules/mob/living/carbon/human/species/station/seromi.dm

@@ -67,6 +67,8 @@
 		)
 	cold_discomfort_level = 180
 
+	minimum_breath_pressure = 12	//Smaller, so needs less air
+
 	has_limbs = list(
 		BP_TORSO =  list("path" = /obj/item/organ/external/chest),
 		BP_GROIN =  list("path" = /obj/item/organ/external/groin),

code/modules/mob/living/carbon/human/species/station/station.dm

@@ -60,6 +60,8 @@
 	heat_level_2 = 480 //Default 400
 	heat_level_3 = 1100 //Default 1000
 
+	minimum_breath_pressure = 18	//Bigger, means they need more air
+
 	spawn_flags = SPECIES_CAN_JOIN | SPECIES_IS_WHITELISTED
 	appearance_flags = HAS_HAIR_COLOR | HAS_LIPS | HAS_UNDERWEAR | HAS_SKIN_COLOR | HAS_EYE_COLOR