|Age||Less than 1 year|
|Cause of Death||Decayed|
|Family|| Patrick Ross † (Father)|
Unnamed prostitute † (Mother)
Various Siblings †
|Abilities||Long tongue is tipped with sharp spines|
|Played by|| Nicholas Vota (Species II)|
Christopher R. Gillum (Species III)
Joel Stoffer (Species III)
|Appearances|| Species II|
Portus is a character from Species III. He is one of the half-breed sons of Patrick Ross with an unknown and unnamed human mother from the previous film. He is one of the surviving half-breeds from the previous film.
After Portus was born to Patrick Ross and an unknown and unnamed human mother, he was taken to a remote shed on the Ross family's property. Later on, Patrick Ross started to help his children to cocoon, awaiting their rebirth as adults that will mate with humans and wipe out humanity so they can rule the planet as the new superior species. After Eve breaks out of the lab and tracks down Patrick on her own, the team follow her to the shed and kill most of Patrick's brood (Portus, along with a few others survive); the explanation for his survival is that he didn't cocoon like most of the others. He is seen at the end in the ambulance with Eve's lifeless body where he looks on as her womb begins to swell indicating an imminent birth after being impregnated by Patrick before his death and hearing her scream as the film ends by cutting to black and going to the credits.
Hours after the events of the previous film, the medical van transporting a half-breed boy named Portus and a lifeless Eve has lost its way, but when the co-driver tries to radio their superiors, the driver stops and holds him at gunpoint. Both are surprised by Portus appearing in the back window and killing the co-driver with his tongue. In the back, the driver finds Portus and a reviving Eve, who goes into labor and gives birth to a newborn girl. While Portus strangles Eve with his tongue, the driver wraps the baby in his jacket and runs off through the forest as a military helicopter finds the deserted van. Portus escapes into the outside world.
After a few weeks or months, Portus is a fully-grown adult who visits Dr. Abbot in his office, asking to see "it" (Eve's offspring), but then partly decays and dies horribly in his chair. Later, Dr. Abbot asked Dean to go with him to his office, and he dissects Portus' dead body and learns that half-breeds are born with weak immune systems, making them vulnerable to common diseases, such as pollen and dust particles, killing them over time.
- Portus has been played by three different actors: by Nicholas Vota as child in Species II, by Christopher R. Gillum as child in Species III, and by Joel Stoffer as adult in Species III.
- Unlike his remaining siblings who also were featured in the film, he was never seen in his alien form.