The first update :)

Central America Caribbean » Curaçao
January 27th 2016

Published: January 27th 2016

So, HI! to everyone reading this!

Currently I am still at home and just testing out how this stuff works, but in only a few short days I will be flying to Curacao :D Sunday the 31st of January to be exact, up, up and away I'll go. I am using this blog to keep facebook and such from getting spammed with all my pictures and stories.

For those interested, I will post the introduction of my research proposal at the end of this post, so you can read about what exactly i will be researching in sunny Curacao. I know it is a bit long, but the short version is: collect shrimps, note their size, gender, colorpattern and host it was living on and do statistics back at home. It means a lot of diving and administration, but hopefully it will be worth it in the end.
So yeah, I guess this blog-thing works and I will be updating it again after I have arrived and settled.

Practical info:

I will be staying at the Carmabi research center and there ought to be wifi over there, so I can keep in touch directly whenever I'm 'home'. Do keep in mind that Curacao is 5 hours earlier than Holland.
Whatsapp: 06-24513155
Skype: SharkBait409
DO NOT send textmessages nor call me, its very expensive. Also DON'T use my voicemail; it doesnt work, and is extremely expensive (I havent figured out how to turn it off yet).

Ok, I guess that was it for now, and I'll see you on the other side...

... of the world :D

INTRO OF PROJECT PROPOSAL

Among the Decapoda caridean shrimps are a widely diverse group, containing over 400 genera and 3500 species (De Grave & Fransen, 2011). With this high diversity, it is not strange these shrimps can be found all over the world (Chace, 1972; Azofeifa-Solano, Elizondo-Coto & Wehrtmann, 2014). A large genus within the Caridea Dana, 1852 is the genus Periclimenes Costa, 1844 (family Palaemonidae Rafinesque, 1815). There are a lot of cryptic species in marine habitats and the Periclimenes is no exception (Knowlton, 1993), cryptic species being defined as “species classified as a single nominal species because they are at least superficially morphologically indistinguishable” (Bickford et al., 2006). These marine shrimp are rarely free-living; most associate with benthic, slow-moving invertebrates. (Silbiger & Childress, 2008; Bruce, 2007).

This symbiosis between shrimps and benthic invertebrates has many advantages for both parties, ranging from protection and food supply to secondary benefits such as cleaning or increased nitrogen concentrations (Limbaugh, Pederson, & Chace, 1961; Silbiger & Childress, 2008; Kotb & Hartnoll, 2002)

Periclimenes rathbunae Schmitt, 1924 is a striking shrimp that lives in shallow tropical waters (Spotte et al. 1991). The adults have an olive-tinged, clear body, covered with patterns of bright orange and white spots. This colour is age-dependent, the juveniles being mostly transparent and without spots. The colouring of the shrimp can also be altered at will: the colour of the body can become more translucent, allowing the light reflecting off the anemone to shine through the shrimp’s body. This gives the shrimp the appearance of having the same colour as the anemone, providing a good camouflage (Spotte et al. 1991; Brinkmann & Fransen, unpublished data). The shrimp is associated with anemone species such as Bartholomea annulata (Le Sueur, 1817), Bunodosoma granuliferum (Le Sueur, 1817), Exaiptasia pallida (Agassiz in Verrill, 1864), Homostichanthus duerdeni Carlgren, 1900, Lebrunia neglecta Duchassaing & Michelotti, 1860 and Stichodactyla helianthus (Ellis, 1768). P. rathbunae has also been found on other hosts, such as the soft coral Eunicea tourneforti Milne Edwards & Haime, 1857 and very rarely (three times) on the corallimorph Ricordea florida Duchassaing & Michelotti, 1860 (Ritson-Williams & Paul, 2007).

However in 2013, an unidentified Periclimenes was also found on the scleractinian coral Dendrogyra cylindrus Ehrenberg, 1834 (Brinkmann & Fransen, unpublished data). Up until then, no other Atlantic shrimp was found to associate with stony corals. This newly obtained species was overall translucent, with little to no colour patterns and sizes much smaller than the P. rathbunae. Because of these key differences in host, colour and size – and the importance of these differences to distinguish sympatric cryptic species (Knowlton, 1993), it was thought to be yet another unidentified cryptic species of Periclimenes (Brinkmann & Fransen, unpublished data).

But, as Brinkmann & Fransen (unpublished data)found, the tiny, translucent shrimp on D. cylindrus was genetically identical to P. rathbunae. This means Dendrogyra cylindrus can be listed as a new host associated with Periclimenes rathbunae. This is the first record of an Atlantic shrimp species associating with a scleractinian coral. This result raises questions as to the population structure of P. rathbunae and ontogenetic host-use patterns.

An explanation could be found in the life history of the porcellanid crab Allopetrolisthes spinifrons (Milne Edwards, 1837). The adults of this crab are only associated with sea anemones, mainly with Phymactis clematis (Drayton in Dana, 1846), but the juveniles can be found on a larger variety of hosts, including gastropods. Habitat restriction during larval settlement has been presented as a reason for this distribution, for the adults are very territorial and live usually solitary on the sea anemones. Even though there is reason to believe the adults do not allow other adults on their host, it has often been found that the adults do share the anemone with juveniles (i.e. non-reproductive individuals). All this evidence hints at a host-switch during the ontogeny (Baeza, Stotz & Thiel, 2001).

This host-use pattern sounds comparable to the pattern found in P. rathbunae, suggesting the maturation of the larvae takes place on the coral D. cylindrus. However the host-use pattern in the A. spinifrons cannot fully explain the distribution of P. rathbunae: ovigerous females have also been found on the D. cylindrus. These females were also smaller and more translucent than the females living on sea anemones (Brinkmann & Fransen, unpublished data).

Another theory is given by McKeon and O’Donnell (2015). They suggest that the size of the host has a direct impact on the size that a shrimp living on the host is able to attain. This is linked to the positive correlation they found between body length and fecundity of the females. This would mean that shrimps on a larger host are larger and that the ovigerous females have therefore a larger fecundity.
The D. cylindrus on which females of P. rathbunae live however, can attain sizes of up to 3 meters. This gives the D. cylindrus a larger surface than the sea anemones, yet the P. rathbunae living on it are smaller.

This research focusses on discovering the host-use patterns of Periclimenes rathbunae.

1. Are there differences in infestation rates between the anemone and coral hosts?

2. Are there differences between shrimp populations with regard to sex, size and fecundity between the anemone and stony coral host species?

3. Is there variation among shrimp populations of the same host species? If so, can this be related to the size of the host?

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