Robert Van Lanen
Distribution: The Giant Sea Spider or, Colossendeis colossea, is typically found anywhere in the bathypelagic zone around the world. Areas include European waters, Gulf of Mexico, and the waters around New Zealand and Australia. It is rarely found at the Antartic convergence (Staples, 2007). It has a comopolitan distribution (Encyclopedia of Life).
Sampling Methods: There is not much one can do in order to sample C. colossea. Most of the samples that have been studied, were brought up from deep sea trawls (Staples, 2007).
Description: The Colossendeis genus is known for its large leg spans which range from about 40-50 cm. All of the species have anywhere from 4-6 different pairs of legs.
Figure 1: C. colossea size compared to human palms (Encyclopedia of Life) Figure 2: Distribution of C. colossea (Encyclopedia of Life)
This species is tyipcally found on seamounts and knolls (Marinespecies.org). It was originally discovered in Austrialia and many describtions of this species comes from the collections there. It has two unpigmented eyes that lack internal tubulars in the post ocular mound. There are scattered spines throughout its segments. Genital pores are present on the surface of a distoventral ridge on its third and fourth legs (Staples, 2007). The trunk and longer leg segments were what was described as a straw-color. The probiscus, palps, and ovigers were a deep orange-red; the ocular tubercle were was a lighter shade and the probiscus was originally a blood red color when it was first retrieved, but it turned into a color that matched the ovigers and palps (Staples, 2007). The eyes were found to be highly reflective or potentially even luminescent (Staples, 2007).
Distinguishing Features: C. colossea and Colossendeis tasmanica share much in common. They are in the same genus however, there are quite a few differences to tell them apart. C. tasmanica has larger genital spores and a longer and more slender palp segment 10. Conspicuous differences in the oviger claw were also reported to give the two different species away. The genital spores were not as much of a difference due to the size difference and age relationship between the spores and the spider. In both specimens, the sex was not determined (Staples, 2007).
Feeding Strategies: Marine scientists have suggested that the feeding style of C. colossea involves it using a well developed probiscus in order to suck up smaller orgainisms that live in the sediment. Paleontologists have used this as a way of determining the feeding strategies of other deep sea spiders that were alive during the Jurrasic period. Some Mesozoic sea spiders have been found to feed upon small ophiuroids, polychaetes, and small bivalves. One species was even found to feed off the mucus that is given off from the surfaces of small echinoderms (Charbonnier 2007).
Adaptations: The reflective eyes of C. colossea are more than likely used to help the spider see in the dark. In the bathypelagic zone (1,000-4,000m), there is little to no sunlight (Marinebio.org). The body color of C. colossea is also an adaptation for the deep. The animals that live at the bottom of the ocean can be transparant, black, or even red. Having an orangish red exoskeleton helps C. colossea due to the absorbance of the color red in the ocean. This allows C. colossea to hide in plain sight from predators (Marinebio.org).
Charbonnier, S., J. Vanner, B. Riou. (2007) "New sea spiders from the Jurassic La Voulte-Sur-Rhone Lagerstatte," Royal Society 282:2555-2561.
"Giant Sea Spider (Colossendius Colossea)- Information on Giant Sea Spider- Encyclopedia of Life." Encyclopedia of Life. N.p., n.d. Web 24 Jan. 2015.
Staples, David A., (2007). "A new species of Colossendeis (Pycnogonida: Colossendeidea) together with records from Australian and New Zealand waters." Memoirs of Museum Victoria 64: 79-94,
"The Deep Sea-- Ocean biology, Marine life, Sea creatures, Marine conservation...-Marinebio.org." MarineBio Conservation Society. Web. Dr. Paul Yancy/MarineBio. Updated 29, December 2011. Acceced 18:03 1/24/2015. <http://marinebio.org/oceans/deep/>.
"WoRMS- World register of Marine Species- Colossendeis Wilson, 1881." WoRMS- World Registers of Marine Species- Colossendeis Colossea Wilson 1881. N.p. n.d. Web. 24 Jan 2015.
IMPORTANCE TO DEEP SEA BIOLOGY:
Eurythenes gryllus is a very cosmopolitan deep sea amphipod. As heterotrophs, they play a very important role in the food web by consuming large particles that fall to depth. Compared to other amphipods, they have a very large biomass.
Eurythenes employ necrophagy and heavily rely on lipid reserves. Upon study, it was found that these hadal animals are much more dependent on lipid reserves than shallow water amphipods (Perrone et al. 2003).
Eurythenes is one of the most widespread amphipods known. It occurs in almost every ocean.
Depth ranges from 550-7800 m. However, there has been some question about vertical species separation.
TYPES OF ENVIRONMENTS:
Eurythenes gryllus are bentho-pelagic animals. They are very common at baited bottom traps.
Occurs in bathyl, abyssal, and hadal zones.
Eurythenes gryllus have a specialized necrophagous feeding mode and also consume large particles that fall to depth. Compared to other amphipods, they are incredibly popular at baited traps and are probably the most bait-attending amphipod. Due to their incredible chemoreceptive tracking and very fast swimming capabilities, they appear at baited traps or carcasses very quickly (Havermans et al. 2013).
Rely heavily on monosaturated fats and lipid reserves.
APPEARANCE AND OTHER SPECIES IT RESEMBLES:
Around 154 cm - giant for an amphipod ! Very similar looking to Eurythenes obesus.
Reddish brown with large armored plates along entire body. Typical amphipod feeding and swimming appendages. White eyes.
Distinguished from similar species by differences in gnathopod structures. Found that species differed with vertical depth. Separation is likely attributed to non-abyssal vs. abyssal individuals (non-abyssal individuals are smaller). After initial description of gnathopod differences, species separation was confirmed by molecular evidence. However, there is not much horizontal difference between populations (Havermans et al 2013).
Observations of E. gryllus have been made often with baited traps because they are so quick to attend and do so at such high populations. Photographic observations have been made at these traps and other carcasses on the seafloor. In addition, a few experiments have deployed traps at the bottom of basins.
An experiment done in 2013 revealed vertical differences in speciation of Eurythenes. It was found that E. gryllus comes from around 5 different distinct lineages. Mentioned above, gnathopod structure and size differences were the tip off to this possible separation, and it was later confirmed with molecular data. Havermans et al used allozymic data to show significant differentiation between seamount slope and abyssal plain specimens. Although vertical differences affected species differentiation to a high degree, there was not much difference in horizontal species (Havermans et al. 2013).
Havermans et al. found 5 differentiated lineages in the bathyal zone, abyssal specimens were all genetically similar. Through rDNA sequences, genetic homogeneity between individuals from two abyssal locations in the Gulf of Mexico was found. However, genetic divergence between those individuals and those isolated in a hadal population was significant (morphological differences also exceeding the threshold of interspecific variability) (Havermans et al. 2013).
This is important because right now, it is thought that there are many overlooked species that are currently identified as Eurythenes gryllus.
Havermans, C., Sonet, G., d'Acoz, C., Nagy, Z., Martin, P., Brix, S., Riehl, T., Agrawal, S., Held, C. Genetic and Morphological Divergences in the Cosmopolitan Deep-Sea Amphipod Eurythenes gryllus Reveal a Diverse Abyss and a Bipolar Species. 2013. Online.
Perrone, F., Croce, N., Dell'anno, A. Biochemical composition and trophic strategies of the amphipod Eurythenes gryllus at hadal depths (Atacama Trench, South Pacific). 2003. Online.
Encylopedia of Life. http://eol.org/pages/325053/overview.
In 2005, the submarine Alvin observed a species never seen before. Now commonly referred to as the Yeti crab, Kiwa hirsuta was observed in hydrothermal vent communities during a Pacific deep sea expedition. One single specimen was taken from a vent named Annie's Anthill (Erhlich 2008).
Fig. 1: Kiwa hirsuta (MBARI)
K. hirsuta has only been observed in the small geographic range covered on the Easter Microplate Expedition. Specimens were observed at depths of around 2200 m "on recent lava flows and areas where warm water was seeping out of the sea floor" (MBARI). Tectonic plates (specifically the Juan Fernandez Plate) are believed to be the main factor limiting the geographic range of this organism. However, not enough research has been done on this area of the deep ocean to confirm this. Organisms have been observed in densities of one or two along hydrothermal vents (Jones 2005).
Fig. 2: Hydrothermal vent sites explored during the expedition (MBARI)
Fig. 3: Cruise range, courtesy of COML
On dives, scientists observed K.hirsuta eating mussels that had cracked when Alvin landed on the sea floor (MBARI). It is hypothesized that bacterial farming may be another source of nutrients for this species. It is known that K. hirsuta's setae are covered with "dense clusters of filamentous microbes" (Erhlich 2008); however, with only one specimen examined, it is difficult to know for certain what role these bacteria play. It is currently beieved that K. hirsuta may use hydrothermal vents to cultivate these chemosynthetic bacteria in its own bacterial farm, providing an alternate source of energy in the challenging environment in which it lives.
Importance to Deep Sea Biology
The discovery of K. hirsuta brought to light not just a new species, but a new family (Kiwaidae) of deep sea crustaceans. "The new genus and species is sufficiently different from all other galatheoid families to justify the establishment of a new family" (Jones 2005). Researchers believe that the Kiwaidae family may be what is known in taxonomy as a basal lineage (COML), meaning that this family may be the primitive ancestor to the other Galatheoidea families.
The morphology of K.hirsuta is similar to other deep sea decapod crustaceans. At first glance, it may just appear to be a large crab. The striking difference lies on it's "hairy" arms. In fact, this is not hair at all. It's setae - a stiff, chitinous structure found on the appendages. K. hirsuta's enigmatic bacterial farmers take refuge in and on the setae.
The Easter Microplate Expedition, on which K. hirsuta was observed and collected, was intended to "locate barriers to gene flow among species of hydrothermal vent organisms" (MBARI). Multiple Alvin dives at several different hydrothermal vents recorded observations of these "yeti crabs." Only one specimen was taken, collected by slurp gun during Alvin's dive (COML). All articles published on K. hirsuta's setae, genetics, or morphology were completed using the specimen collected on this expedition.
Fig. 4: In situ observations of K. hirsuta recorded aboard the Alvin (Jones 2005).
In Polynesian mythology, Kiwa is the godess of shellfish (Jones 2005). In Latin, hirsuta means "hairy." While this research team was the first to collect a sample and publish an article about K. hirsuta, they were in fact not the first to lay eyes on this species. In 2001, the German cruise ship "Sonne SO-157" documented this creature as "type Shinkaiinae" (EOL). They did not collect a sample.
Macpherson, Enrique, William Jones, and Michel Segonzec. "A New Squat Lobster Family of Galatheoidea (Crustacea, Decapoda, Anomura) from the Hydrothermal Vents of the Pacific-Antarctic Ridge." Zoosystema (2005): 709-23. Web. 2 Feb. 2015.
Goffredi, Shana K., William J. Jones, Hermann Erhlich, Armin Springer, and Robert C. Vrijenhoek. "Epibiotic Bacteria Associated with the Recently Discovered Yeti Crab, Kiwa Hirsuta." Environmental Microbiology 10.10 (2008): 2623-634. Web.
"Discovery of the "Yeti Crab." Monterey Bay Aquarium Research Institute. Web. 2 Feb. 2015.
"Kiwa Hirsuta: New Species." http://www.coml.org/. Census of Marine Life. Web. 2 Feb. 2015.
"Descriptions and Articles about the Yeti Crab (Kiwa Hirsuta)." Encyclopedia of Life. Web. 2 Feb. 2015.
Japanese Spider Crab (Macrocheira kaempferi)
The Japanese Spider Crab (Macrocheira kaempferi) is a wonder of the deep sea and one of the largest known arthropods today. It received its interesting name due to its close resemblance to a spider. This crab has a round body covered with spikes with very long legs and two front claws. This unique species of crab has been reported to grow up to 12 feet across and weigh up to 45 pounds (Japanese). It is even known to live up to 100 years (Giant)! Its extremely large size and long legs as well as reddish color sets it apart from other species of deep sea crabs.
Distribution and Types of Environments:
The Japanese Spider Crab is found in the Pacific Ocean around Japan at depths anywhere between 50 meters (during breeding season) to 600 meters, which makes it an impressive benthic species that can adapt to the challenges of living in the deep ocean. It is mostly found in the Sagami, Suruga, and Tosa bays at temperate waters around 10 degrees Celsius (Descriptions). Its ideal habitats are vents and smaller holes in the deeper part of the ocean (Japanese).
Distribution of M. kaempferi in Japan
Feeding and Predation Strategy:
This crab is an omnivore and eats all kinds of plants and animals. It can even scavenge for dead animals if it needs to. It has the ability to manipulate its front claws to force open mollusk shells as well as scrape the ocean floor for algae and other plants (Japanese). It uses camouflage as well as its bumpy shell to hide from its predators. It can even provide a home on its shell for sponges and other small animals to use as another form of camouflage (Giant). It has been known to actively search and place organisms on the back of its shell to hide itself from predators such as octopus (Japanese). These animals are not active hunters and therefore don’t have much interaction with other organisms. They like to search for food alone and rarely interact even with other Spider Crabs (Macrocheira).
Female crabs ascend from their usual deeper depths to around 50 meters during breeding season. The females carry the fertilized eggs on their abdomen until the eggs are ready to hatch into planktonic larvae. These larvae have no resemblance to a mature Spider Crab; they are very small transparent organisms with a round and legless body (Japanese). A study published in 1993 looked at how temperature affects the production of larvae. Results showed that the optimum rearing temperature for this species was between 15 to 18 degrees Celsius. It was also noted that the planktonic larval stage could last anywhere from one to three months. Due to these depth and time restrictions it was determined that the larvae needed to remain in shallower depths, which explains why the crabs make such a drastic ascent to the surface to reproduce (Okamoto 419). These larvae will float as plankton through the water column and at the surface of the ocean with no guidance from the mother (Macrocheira).
Larval Stage of M. kaempferi
M. kaempferi has a useful role in the deep sea biological ecosystem. It is not known to be an active predator however, does help regulate the amount of dead biomass on the sea floor through feeding and scavenging. This species provides a home for sponges and other organisms on its shell and can even provide new habitats and food sources for the organisms. This species also has a large impact on the Japanese culture itself. These crabs are often used as a delicacy in many places, eaten both raw and cooked (Macrocheira). These crabs are studied by multiple methods since their depths have such variation. It’s easier to observe and study these animals during their breeding season when they are in shallower waters. However, when they are at depths of 500 meters it becomes a little more complicated. Scientists have mostly collected data through government-funded expeditions into the deep ocean with ROVs, AUVs, and other deep-sea equipment (Adaptations).
"Adaptations of Crabs to Life in the Deep Sea." NOAA Ocean Explorer Podcast RSS. Web. 5 Feb. 2015. <http://oceanexplorer.noaa.gov/explorations/02alaska/background/crabs/crabs.html>.
"Descriptions and Articles about the Japanese Spider Crab (Macrocheira Kaempferi) - Encyclopedia of Life." Encyclopedia of Life. Web. 3 Feb. 2015. <http://eol.org/pages/2924326/details#distribution>.
"Giant Japanese Spider Crab." Giant Japanese Spider Crab. Web. 3 Feb. 2015. <http://www.tnaqua.org/our-animals/invertebrates/giant-japanese-spider-crab>.
"Japanese Spider Crab." Japanese Spider Crab. Web. 3 Feb. 2015. <http://animalguide.georgiaaquarium.org/home/galleries/cold-water-quest/gallery-animals/japanese-spider-crab>.
"Macrocheira Kaempferi." Animal Diversity Web. Web. 5 Feb. 2015. <http://animaldiversity.org/accounts/Macrocheira_kaempferi/>.
Okamoto, Kazutoshi. "Studies on the Larval Rearing of Giant Spider Crab, Macrocheira Kaempferi-III. Influence of Temperature on Survival and Growth of Larvae of the Giant Spider Crab Macrocheira Kaempferi(Crustacea, Decapoda, Majidae)." NIppon Suisan Gakkaishi 59.3 (1993): 419-24. Print.
The Porcupine Crab
Kingdom: Animalia Phylum: Arthropoda Class: Malacostraca Order: Decapoda Family: Lithodidae
Genus: Neolithodes Species: grimaldii
Appearance: The porcupine crab has a dark red color and long sharp spines all over its body. It has three pairs of walking legs and one pair of claws. There is another pair of legs under the carapace of the crab that is used for cleaning the gills. The left claw is smaller than the right and is used most likely for handling food while the bigger claw is used for crushing (Encyclopedia of Life). Female porcupine crabs are smaller than the males. Their carapace lengths can grow up to 160 mm. Male crabs carapace lengths have been measured to 180 mm. Porcupine crabs are a member of the king crab family (Hearn). Also males and females are easily distinguishable by external features in the abdomen. If it was a female there would be eggs under the abdomen or the presence of the funicular. The funicular is more developed in mature females (He).
Distribution: The porcupine crab is found in deep water in depths of 500 fathoms (914 meters) and beyond (Hearn). They range from both sides of the Atlantic Ocean with southern limits of North Carolina on the west and Cape Verde Island on the east. (He)
Types of environments: Neolithodes grimaldii is found in the benthic zone on the sea bed along the continental slope (Hearn).
Feeding: According to the Hearn, the feeding strategy for the porcupine crab is not known specifically. An experiment was set up to bait porcupine crabs with many different food options. This experiment was unsuccessful and they only caught one crab. Most of this crab’s relatives eat live creatures such as sea stars or other crabs. If they can’t find fresh food they feed on leftover scrapes or dead matter that falls from above (Monterey Bay).
Reproduction/Growth: The eggs of this species are black or dark brown and larger than other related species. The females spawn fewer eggs and have a unique adaptation to being in such deep water. This adaption is that they do not have the ability to form new eggs in the gonads while incubating eggs under the abdomen. Porcupine crabs grow by molting like many other crustaceans but it doesn’t seem to be dependent on the season (Hearn).
Importance to Deep Sea Biology: This creature is important to deep sea biology because it helps discover more of the genetic diversity down in the deep sea where it is hard to study many creatures.
How observations have been made: Observations on this species have been made by fishermen catching these creatures in gillnets and trawls along the ocean bottom. Then they would be studied and mostly released (He).
He, P. 2005. Characteristics of bycatch of porcupine crabs, Neolithodes grimaldii (Milne-Edwards and Bouvier, 1894) from deepwater turbot gillnets in the northwest Atlantic. Fisheries Research. 74:35-43.
Hearn, D. Experimental Fishery- Porcupine Crab with Pots. Department of Fisheries and Aquaculture. Web. http://www.fishaq.gov.nl.ca/research_development/fdp/fdp_151.pdf. (2015, February 5).
Neolithodes grimaldii Spiny King Crab. Encyclopedia of Life. Web. http://eol.org/pages/346507/overview. (2015, February 5).
Spiny king crab. Monterey Bay Aquarium. Web. http://www.montereybayaquarium.org/animal-guide/invertebrates/spiny-king-crab. (2015, February 5).