Possibly. I've heard of this behavior happening before, but I don't know that anyone has actually confirmed what happens to the critters the goby catches and hands off to the shrimp (IIRC, I've heard of at least one member here on R2R having their goby bring a critter in only for the critter to leave later, but there's no guarantee that every critter leaves) - it's suspected that these critters are generally eaten by the shrimp, but, currently, that's just speculation with no evidence (at least that I'm aware of) to back it up (it wouldn't surprise me, there's just no evidence yet).
So, the goby might have fed the shrimp, it might have given the shrimp the hermit so the shrimp could prep it/hold it for the goby to eat later, they might use it as decor/part of the structure of the burrow, the goby might have gotten it as a "pet" for the shrimp (yes, this is unlikely), this could be some form of play like how dolphins play with rocks and stuff, etc.As stated, these guys really aren't the vicious hunters they're made out to be.
They're actually omnivores (see the quote below), and the tiger pistol (Alpehus bellulus) is one of two species so far (Alpheus randalli being the other - see the link in the quote below) that has been confirmed to feed on its goby partner's feces,* so adding a goby may very well help on the off-chance that your shrimp actually is being aggressive:
Some more info from the article linked in the quote above:A quick note here on pistol shrimp diet - pistol shrimp do not seem to be predatory, rather they seem to be more opportunistic, omnivorous scavengers (the only "hunting" that seems to take place outside of the burrow is done by the gobies, not the shrimp, and - to my knowledge - no one has ever confirmed if the shrimp actually eat the "prey" brought to them by the gobies; it might be that the goby eats them rather than the shrimp, or the shrimp might eat them as people generally assume):
Goby and shrimp associations: more than meets the eye - Coral Reefs
link.springer.com
"Diet analyses of shrimp associates indicate copepods, interstitial matter, and seagrass as main food items. Incidental observations revealed a more varied diet, facilitated by goby associates. Cryptocentrus cinctus and C. singapurensis [= C. leptocephalus] were previously reported to introduce items such as algae and bivalves into burrows for associate shrimps. We observed the goby, Amblyeleotris latifasciata, capturing a small crab near the burrow entrance and carrying this prey item toward the burrow entrance. Upon arrival, it rapidly moved up and down, a characteristic behavior we can best describe as ‘jumping’. The shrimp emerged from the burrow and proceeded to remove the entire prey item from the mouth of the goby, without resistance or struggle from the latter, before retreating into the burrow (Fig. 1)."
Additionally, as noted in the article linked above, at least some Alpheus spp. clean their gobies by eating the parasites off of them.
*Source:
