Heather Spence, Marine Biologist
Orchestrating Coastal Marine Ecology Investigation and Outreach

Heather Spence, Marine Biologist

Snapping Shrimp Publication

Here it is – ENJOY (full text now available Download PDF)

Morphological and Developmental Differences in Three Species of the Snapping Shrimp Genus Alpheus
(Crustacea, Decapoda)
Heather R. Spence1 and Robert E. Knowlton2,*
Abstract – Living, freshly collected individuals of three species of snapping shrimps were studied to determine any differing morphological, developmental, and ecological features: Alpheus heterochaelis, collected from Beaufort, NC; A. angulosus, found mainly in Jacksonville, FL, but also at one site in Beaufort; and A. estuariensis, collected at another Jacksonville site. Structural characteristics of these superfi cially
similar species are summarized, with particular attention to coloration. Adult A. angulosus individuals have blue-green 2nd antennal fl agella (vs. tan in the other two species) that are signifi cantly shorter than those of A. heterochaelis. Alpheus angulosus and A. estuariensis bear smaller eggs (<1 mm, regardless of embryonic stage) than A. heterochaelis (>1 mm), and the former species displays the zoea larval form
typical of alpheids (vs. abbreviated larval development in A. heterochaelis).

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Spiny Lobster Research, Mexico

Spiny lobsters are an important fishery in the MesoAmerican reef system, and efforts are being made to promote the sustainability of their populations. In Quintana Roo, Mexico, I am working with the National Parks office on a new project to attract and provide habitat for juvenile lobsters in the protected area of the coast of Isla Mujeres (a critical breeding area).

The area we chose named “Sac Bajo” is shallow, with an ‘artificial reef.’ Around the world there are many types of artificial reefs, including sunken ships, which serve to provide additional habitat options for organisms whichhave lost much of their natural habitat. These structures also provide protection to the coast, and in the case of Sac Bajo in particular, an alternative destination for tourists to limit destruction of the natural reef. The artificial reef at Sac Bajo is constructed through the use of reef balls, which are molded concrete hollow mounds about 1m in diameter. Corals are planted on them, and the complex structure attracts a variety of fish and other organisms. At Sac Bajo there are two different styles of reef ball, one with large round holes scattered all over the sides, and one with horizontal tiered holes, aptly named “layer cakes.” These layer cakes are more attractive habitat to lobsters, which aggregate in the spaces with their antennae pointed out.

Spiny lobsters, and other crustaceans such as shrimp and crabs, have a life cycle in which their eggs hatch larvae, and the larvae move away from the shore, develop through a number of stages, then move back in to shallow water to ‘settle.’ Once settled they are considered juveniles, and look like miniature versions of the adults. In the case of these lobsters, the juveniles nestle into a part of the coral reef, and grow to adults.

When the larvae are seeking a place to settle, they prefer a complex, algae-type habitat. Then, when they transform into juveniles, they prefer a coral reef/rocky type habitat. In Sac Bajo, the layer cake reef balls provide the rocky habitat for the juveniles, but not the algae-type habitat for the larvae. So, we decided to place larval collectors of the type used in studies monitoring the influx of larvae, because they are known to provide habitat suitable for the larvae. These collectors float at the surface, and are anchored to the sea floor. In this case, we could anchor them to the layer cakes, and the rope would provide a ladder of sorts for the lobsters to move down into the new habitat.

There are various types of collectors, we chose to use the economical and functional GuSI type collector, which is rather like a bucket wearing a hula skirt. The ‘skirt’ is actually bunches of filastica which is strips of plastic, which serve as a durable algae-like material for the lobsters to hide in.

The construction, deployment and monitoring of the collectors is made possible by the collaboration of the national park guards (guardaparques) who go out every day to patrol the protected areas. Their experience on the water and in the deployment of buoys provides invaluable assistance in carrying out this research.

Sac Bajo has a unique set of challenges for this research, as not only do we have to design collectors to appeal to lobster larvae, we must protect them from possible storms and also deal with boats, tourists and illegal fishing. In addition, lack of resources limits accessibility to the field site and number of collectors that can be deployed. However, these are obstacles that can be overcome and we are excited about the potential applications for this research, not just in enhancing the lobster population in the area but also in assisting a new effort to start lobster aquaculture on Isla Mujeres.

Sac Bajo Surface Collector

Underwater view up at collector, anchored to layer cake

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Spiny Lobsters

are like cellists

they have a very specialized parts of their antennae that they rub against their head like a bow on a string

check out their sounds as well as other sea creatures’ at – http://www.dosits.org/

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Snapping Shrimp

Did you know that perhaps the loudest sound in shallow waters is made by animals the size of your pinky finger?

Snapping shrimp have claws (which makes them look a bit like baby lobsters), but one claw is much bigger than the other. They shut or ‘snap’ their big claw so quickly that it creates a vacuum bubble – the bubble bursts and produces a loud popping sound! (described by Versluis et al, 2000 in journal Science)

Next time you’re walking on a beach or a pier listen for their distinctive crackling sound!

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