Barnacles, limpets or gribbles?

The Leafless walked in from a walk by the beach to tell us about a log which had washed in. She said it was full of shells. I thought it might be barnacles. I finished my tea and walked out to look at the log.

It was a freshly broken branch of a tree, and it had been colonized by bivalves. Clearly these were not barnacles or limpets. Were they gribbles? I didn’t think they were. They could be piddocks; those are bivalves. But the piddock shells I got to see in a few days did not look like these. I wonder what these mysterious creatures are. Look at the movement of the shells on the extreme left in the 7th second of the video below: they look like real bivalves.

I wonder if anyone can help me figure out what they are.


How to spot a carnivore

If you walk along the beach and find a group of people clustered around something that has washed up, hotly discussing whether it is a lobster, you would be sure you had fallen in with a bunch of confirmed carnivores.

The Leafless and The Family stopped at this head as I was taking photos elsewhere on the beach. I realized they must have come on something interesting, so I walked over. The Family thought it was some kind of a lobster. The Leafless asked "Wouldn’t it have claws?". I agreed with both, but it was a bit of a mystery, as we all took photos of this beautiful head.

Spiny lobsters, also known as langouste or rock lobsters, are a family (Palinuridae) of about 60 species of achelate crustaceans, in the Decapoda Reptantia. -Wikipedia

A little research cleared this up. Technically we’d seen the head of a spiny lobster. I think I’ve eaten them in France. I’m certain that The Family and I have walked around farmer’s markets where there were Langoustes on sale. Energized by this sight we order a lobster for dinner. It wasn’t available, so we settled for crabs instead. If you see a crustacean with a long spiny antenna and small or non-existent claws, it is almost certainly a spiny lobster.

Fish in a tide pool

On arrival at Neil Island we met a young auto driver called Suman. He turned out to be very articulate, and had a very pleasant way of explaining to us when we disagreed on anything: including fares. There were many pleasant auto drivers on the island, but of those we met he was the most articulate. Once we were at a loose end in Bharatpur beach, when we met him.sitapurrocks He asked where we wanted to go, and we said that we would go to whichever place he wanted to show us. He took us to Sitapur beach.

That was the first time we saw this beach, with its spectacular crescent of yellow sand, and the wonderful submerged layers of rocks. You can see the clarity of the water in the photo above. I think the rocks must have been heaved up in the 2004 earthquake. I loved the very eroded flat slabs of rock, some with holes bored by piddocks.

Rocks around Sitapur beach, Neil Island, Andaman

The tide was out, and we walked out over the bare rocks to peer into little tide pools. Some of them had tiny fish which would dart away as soon as they saw something looming above the water. Eventually I captured the featured photo by crouching low on a rock until the fish came to rest. Until I saw the photo, I hadn’t noticed the bubbles at the tips of the fronds of seaweed.

The beach was empty except for us and a French couple swimming in a deep pool among the rocks. We walked up to a distant rock fall and came back. Suman was waiting expectantly, and his face lit up when we answered his unasked question by saying this was a beautiful spot.

Eating in or eating out?

The little islands of Ritchie’s archipelago have small populations by Indian standards. Neil Island has a permanent population of about 3000, with about that many more tourists in peak season. A large fraction of the population runs restaurants. Signs such as the one in the featured photo were common. We also read one which promised "North and South Indian, Bengali, Continental, Chinese, Israeli and Bhutanese food". I had looked at these signs as indicators of where most visitors came from, but the reference to Bhutanese was a jolt. It is unlikely that there are many Bhutanese tourists here. Perhaps it is a nod to the fact that momos are popular all across the northern part of the country.

Typical beach eatery in Neil Island, Andaman

On our first day in the island, we came across this little stall on the beach. While we had a tea, the man told us about what he could get us for dinner. His recommendation was lobsters, and the price he offered was good. He insisted that The Family take down his phone number. If we ordered he would deliver the dish to our room in the hotel. Unfortunately, we never got around to ordering. There are too many walk-in options. What sea food we ate on the island was wonderfully fresh.

Reading on the beach

There were lots of animals on beaches and in the sea around Neil Island, but Lepus timidus were not among them. So the sign in the featured photo had to be in error. Also, as one of my nieces pointed out, the buoy is too big for any known hare. We saw many interesting signs on Bharatpur beach, but this probably takes the award for the zaniest mistake.

Glass-bottomed boats, Neil Island, Andaman

You can take glass-bottomed boats out of Bharatpur beach to see corals. Since the cut on my leg prevented me from getting into the water, I took this more distant view of the sea bottom. The boats had terrific names; two of the best are in the photo above. I liked "O. B. Sea Prasad", whose subtext every Indian will instantly follow. A gloss for others: affirmative action in India is mainly based on castes, and OBC stands for Other Backward Castes. This boat was probably bought using an affirmative action bank-loan. The name of the boat standing next to it is a really zany take on Santa Cruz. There may have been an effort at a pun: Santa Cruise, but it didn’t come out very well.

I loved reading on the beach.

Jarawa: a pre-agricultural people

The Andaman groups of islands were perhaps first settled by humanity around 26000 years ago, at the peak of the ice age. At that time it was connected to Myanmar by land bridges. After the end of the ice age, when the seas rose, these islands were cut off. This story is currently supported by genetic data. Contact with the rest of humanity came again when imperial British soldiers settled in Andaman in 1789. Within four years influenza, measles and pneumonia wiped out about 90% of the population. The Japanese bombed the islands in 1943, targeting the native population. In the early years of the Indian republic conflict with tribals continued.

As I have suggested previously, it is probable that some disease was introduced among the coastal groups by Lieutenant Colebrooke and Blair’s first settlement in 1789, resulting in a marked reduction of their population. The four years that the British occupied their initial site on the south-east of South Andaman were sufficient to have decimated the coastal populations of the groups referred to as Jarawa by the Aka-bea-da.
Sita Venkateswar (2004)

Of the 13 linguistic groups found in the 19th century, only the Jarawa, Onge and North Sentinelese survive. The Indian republic now respects the wishes of the Jarawa and North Sentinelese people to be left alone. It was estimated in 2003 that there are less than 100 of each tribe left.

We traveled north from Port Blair along the Andaman Trunk Road, passing through the Jarawa reserve forest. In order to minimize impact on the tribals, vehicles are only allowed in a small number of convoys at fixed times of the day. Vehicles are supposed to maintain a constant speed, and stay within eye sight of the one in front. The Jarawa people live in a pre-agricultural state. The Family and I were talking about what it might mean not to have agriculture. The first thing we thought of was the relative lack of surplus food. At home we store very little meat and fish. Most of the food that we store at home are grains, sugar, vegetables and fruits, spices. If we had no agriculture, we probably would not store food. Then would we store anything else at home? If we did not store anything, would we have an economy?

Our first view of a group of Jarawa tribes people came as a surprise. We saw a man and a woman with a child next to the road. They were short and slender, but extremely muscular, dark skinned, and with curly dark brown or black hair. We had earlier discussed whether or not to photograph any Jarawa people we saw, and agreed that we would extend to them the same courtesy that we would to any other person: no portraits unless we could, in principle, ask their permission. Since we knew that we had no common language, this meant that we would not take photos. It turned out, in any case, that photography was forbidden, The woman had on a cotton gown, the child had shorts and a t-shirt. All three wore head bands made of tree bark, which seemed to be decorated. Senthil, who was driving, explained that if Jarawas come to a hospital, then they have the option of taking clothes. The group was angry, and the man shook a spear at us. We later found that the reason was that the car in front of us had slowed down, and one person had taken several photos of the group.

We find various of the features of Jarawa art duplicated in known non-iconic Pleistocene and Early Holocene traditions, despite the significant differences in the media used and the very sporadic nature of the archaeological record.
M. Sreenathan, V.R. Rao and R.G. Bednarik (2008)

We were surprised by the number of tribes people we saw: more than ten. We saw in passing a Jarawa woman making something out of tree bark, probably the head and waist decorations that they wear. There are papers on Jarawa art available in journals. We heard that they have metals now, and they make arrowheads out of them. In about four hours of driving along the road we saw ten of the Jarawas. That is a significant fraction of the tribe’s population. This is perhaps a very strong indication that the tribal culture has been badly disrupted by continuing contact with outside. We saw an Indian man in black uniform inside the jungle, perhaps one of the anthropologists who live and work with Jarawas. So contact with the Jarawas continues. Clothing, attempts to teach them Hindi, and trying to get youngsters to school, are among the cultural pressures that still remain.

It is said that the normal diet of the Jarawa hunter-gatherers consists of fish, wild pigs, and turtles, fruits, roots, tubers and honey. The Family reminded me of the effect of the agricultural revolution on changes in human oral bacteria: a very recent discovery. It seems that our dental and oral bacteria changed after the invention of agriculture in order to accommodate the new human diet. She speculated that the Jarawa oral bacteria could be very different, and much more healthy. This could also be a reason that the tribals fall ill if they switch their diets to a modern industrial-agricultural diet.

There is so much human diversity to be preserved here! Just a study of the oral flora of Jarawa tribals could teach us so many things about our own lack of health. How much more there could be to learn.

A Beach in the Anthropocene

Walking on the beach, looking for odd sea creatures, I found that I was constantly shifting my angle of view so that I could take photos without including a lot of garbage. After some time I wondered why I was doing that. Wasn’t there an equally interesting story in the things I was trying to avoid? Take the featured photo: the tracks in the sand belong to molluscs and crabs, but the largest object there is a piece of long-lasting plastic garbage which has washed up from the ocean. It looked like a container of machine oil to me.

Garbage washed up on Neil Island, Andaman

You have probably read the same articles about garbage that I have, so you know about the continent sized floating islands of garbage in the middle of the world’s large oceans. The Andaman islands lie a little west of Myanmar, Thailand, Malayasia and Indonesia. As a result, garbage from these countries lands on the beaches of Andamans on their way to the Indian Ocean gyre. This is not a guess: it is the result of looking at innumerable labels on plastic garbage through a morning. You can verify it from the photos here.

Garbage washed up on Neil Island, Andaman Garbage washed up on Neil Island, Andaman Garbage washed up on Neil Island, Andaman
Garbage washed up on Neil Island, Andaman Garbage washed up on Neil Island, Andaman Garbage washed up on Neil Island, Andaman

Garbage from India does not wash up in the Andamans. I guess that lands up either directly in the Indian Ocean garbage patch, or on the beaches of Lakshadeep and Sri Lanka. I grew up with romantic stories of messages in bottles found on beaches. Today the romance is gone; bottles are the most common man-made objects on a beach, as you can see from the photos above. The message that these bottles bring us are of the incredible waste that all couintries produce today.

Garbage washed up on Neil Island, Andaman

If the can of machine oil had an ambiguous origin, this gizmo almost certainly has come from a boat. Was it tossed overboard, or did it fall off because it was stowed carelessly? It does not really matter. It has come to rest on a bed of broken corals. By the time the corals weather down to the white sands of these beaches, they will have incorporated bits of this plastic. Even now, when we go for a swim we probably come out the water with bits of plastic clinging to us along with the sand.

Garbage washed up on Neil Island, Andaman

The kind of garbage you see in this photo is everywhere: bits of thermocol, little plastic containers. Industrial civilization produces them with such abandon that a little inattention on our parts can cause it to turn into a pollutant. Think of this for the moment: how often do you handle plastic packaging of any kind? Once every twenty minutes? Is it possible for you to be mindful of where every bit of the packaging you handled in one day has gone? Even with the best will in the world, you will not be able to answer "yes". That is the tragedy of the anthropocene.

Bitten by a radioactive mollusc?

It’s not very often than I hear The Family yelp. When she did, I tore myself away from the ghost crab I was trying to photograph to check on her. She was holding a long conical shell and looking very white. As I rushed up to her I remembered a friend of ours who was working on poisonous cone snails. Was she holding one?

Fortunately, she was not. The creature in the photo you see above had been startled when The Family picked it up from the beach, looked out and used its pincers to explore its surroundings. That’s when I heard the sound from its surroundings. Once we realized that it was not poisonous, I took a few photos before putting it back. It was the second day of Christmas.

Ghost crab, Neil Island, Andaman

Meanwhile the ghost crab (photo above) would have disappeared. I saw it first as something scurrying over the white sand at the edge of my vision. I looked around and couldn’t see it. But then it moved again as I was looking at it. It didn’t like my camera, and kept scuttling away. Eventually, as it rested on a little stone, I managed to get a photo. Even in the photo it is hard to see it clearly. I’ve enhanced the contrast to make it visible. I’m sure I can see ten legs, but how many eyes does it have, and where?

When you look at the photo above, you notice the holes in the stone. What makes them? Jessica had some answers: in a much colder sea there are creatures called rock borers (duh), piddocks, and sponges.

Piece of a sea sponge, Neil Island, Andaman

I would not have believed this about sea sponges. But on the third day of Christmas my niece got for me a sea sponge on a rock. We admired it together. The branching filaments of the sponge allow it to sample the water that flows through it, and filter out food. I noticed that the rock on which it grew was full of holes. As for piddocks, I only saw these bivalves the next day.

Gribble holes in wood, Neil Island, Andaman

On the fourth day of Christmas, The Family and I admired this large piece of driftwood we had to cross. The beautiful surface has been created by living creatures. In the waters around the Andaman islands, the wood borers are mainly molluscs called shipworms (family Teredinidae) and crustaceans called gribbles. It turns out that there is an immense scientific literature on these, because of the harm they do to wooden structures. However, many of the papers are on the biology and physiology of these creatures. One of the few things I learnt was that shipworms and gribbles eat wood, but piddocks just make holes where they can sit safely. In the photo above you can see a few shells lodges snugly in holes in the wood; these are probably piddocks. Eventually I came across a post which takes you deeper into the world of wood eaters in the sea.

I think these were more interesting than partridges, turtle doves, French hens and calling birds. And no, The Family still hasn’t developed a mollusc sense.

The private life of a star

We walked out into a bed of dead corals at sunset, meaning to walk to a point where the corals were alive. The tide was coming in, and we had little time. But I got distracted. There were tentacles waving below the surface of the water. When I looked closer I saw a strange starfish, climbing up a submerged stone using all five tentacles around its round body.

Once I knew what to look for I could see them everywhere. They would usually have a bolt hole where they would retreat to hide or feed. Feeding consisted of pushing a couple of tentacles out of its cave and agitating the water around it. Presumably this enabled them to catch tiny organisms floating in the water. It looked like a child stuffing her mouth while out picking blueberries.

Crawling cowrie!

Not being able to get into the water during my vacation meant that I prowled the beaches with my camera prying into the private lives of every visitor. One of my interesting encounters was with a cowrie. I’ve handled these shells now and then. When I was a child, I used to like the small white ones.Cowrie keeps a watch on me in Neil Island, Andaman I saw one lying on the beach, and I moved to pick it up. Then it moved!

It scurried across the sand, pushing itself with its claws. I tried to take a photo. As I moved the camera towards it, it hunkered down. The claws disappeared into the shell. I could see its eye stalks waving uncertainly (photo to the right, above). I drew back, waiting to see what it would do.

After some waiting, it decided to start moving again. Its claws came out, and it pushed itself rapidly across the sand with them. I brought my camera forward, and it scurried. The eyestalks remained on the camera, as I drew back and took the featured photo.

The defensive action of molluscs is to hunker down, and withdraw from the world. I found it interesting, that this one was curious enough to keep its eyes out.