08 de julio de 2023

Yellowline Arrow Crab, Stenorhynchus seticornis

I noticed that observations of many Yellowline Arrow Crabs, Stenorhynchus seticornis do not have research grade IDs, so I did some research to find out why. I found a 1988 paper that identifies two species of Stenorhynchus in the Western Atlantic/Caribbean, Yellowline Arrow Crab, Stenorhynchus seticornis and Red Arrow Crab, Stenorhynchus yangi:

"Stenorhynchus yangi, A New Western Atlantic Species Of Arrow Crab Stenorhynchus seticornis (Herbst, 1788)" - https://biostor.org/reference/74586.

There are only two other Stenorhynchus species, Stenorhynchus debilis (S. I. Smith, 1871) in the Eastern Pacific and Stenorhynchus lanceolatus (Brullé, 1837) in the Eastern Atlantic.

Figure 1 in the paper shows two easily identifiable feathers that set the species apart. S. seticornis had a "hairy" rostrum that is twice the length of it's carapace. S. yangi's rostrum is smooth (no hair) and is about the same length as the carapace measuring from the eyes.

The paper includes the depths at which the two species were collected, and it appears that S. yangi is a deep water species, whereas S. seticornis is found within scuba depth (see Tables 1 and 2 in the paper).

After reviewing over 700 observations of Stenorhynchus seticornis here on iNaturalist, I only found one observation that appears to be S. yangi, and it was found in the Gulf of Mexico: https://www.inaturalist.org/observations/6716028

I have since gone through and added IDs to most of the Yellowline Arrow Crabs that were not research grade and in which the rostrum clearly fits the description in the paper.

In conclusion, the Yellowline Arrow Crab, Stenorhynchus seticornis is very easy to ID, so there is no reason to hold back.

Publicado el julio 8, 2023 05:28 TARDE por coralreefdreams coralreefdreams | 1 comentario | Deja un comentario