Monocorophium acherusicum (A. Costa, 1853)*
Zebra-slijkgarnaal
Zeelandbrug, the Netherlands, 7-7-2025. In vitro photo male specimen A, L: 8 mm including antennae, 17-7-2025. Found between tubes of
Ericthonius didymus.
Zeelandbrug, the Netherlands, 7-7-2025. In vitro photo male specimen A, 17-7-2025.
Zeelandbrug, the Netherlands, 7-7-2025. In vitro photo male specimen A, 17-7-2025.
Zeelandbrug, the Netherlands, 7-7-2025. In vitro photo male specimen A, 17-7-2025. Found between tubes of
Ericthonius didymus (Pacifische klauwvlokreeft)(on photo), see next two photos.
Zeelandbrug, the Netherlands, 7-7-2025. In vitro photo male specimen A, 17-7-2025. Found between tubes of
Ericthonius didymus (Pacifische klauwvlokreeft)(on photo), see next two photos.
Zeelandbrug, the Netherlands, 7-7-2025. Habitat shared with - among other species - Ericthonius didymus (Pacifische klauwvlokreeft), Caprella mutica (Japanese skeleton shrimp - Harige spookkreeft) and Jassa species.
Zeelandbrug, the Netherlands, 7-7-2025. See orange marker. Habitat shared with - among other species -
Ericthonius didymus (Pacifische klauwvlokreeft),
Caprella mutica (Japanese skeleton shrimp - Harige spookkreeft) and
Jassa species.
* Identified by Marco Faasse and Ton van Haaren (July 2025).
Marco: "Photos often don't show the characteristics you need, but based on the broad, flat first segments of the first antennae, I think it's M. acherusicum. A characteristic not listed in keys. Only so clearly in males, I think. I don't know what's on the posterior end, but I'd guess sessile cilia. They often sit specifically on certain crustaceans. I see some projections. I wouldn't completely rule out a sponge, but the layer is quite thin for a sponge."
Ton: "It looks convincingly like a male M. acherusicum to me. Fused urosome segments without a lateral edge separate Monocorophium from Apocorophium. The pigment spot on the head is a narrow stripe along the leading edge, and there is a very short rostrum, so it is not an M. insidiosum. The underside of the first segment of the first antennae (the upper pair) has only a few spines and the segment is slightly raised, so it is an M. acherusicum. M. sextonae has more spines and the segment is not raised."
