Can Spiders See In The Dark?

Survival is crucial for tiny crawling creatures like the spider. And their more than 35,000 species worldwide have survived the ravages of time, adverse climate conditions, and the threat of predators, including insects, small animals, even humans. They have learned to adapt and change over thousand of years. And one of the observable habits that some spider species has adapted to is the ability to move about and hunt at night. But, can spiders see in the dark?

Can spiders see in the dark?

Most spiders (99%) have eight eyes. So, you’d think that they see clearly. But the news (good or bad?) is, they don’t. Most spiders don’t see clearly, they have blurred vision, even during the day. But not all. Some hunters have clear daytime vision. But how about during the night or in the dark — Can spiders see in the dark or at night? Hardly. But not all — there are spiders that see in the dark.

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How spiders see in the dark.

Most spiders who move about at night don’t rely on their sense of sight. Spiders who go out at night, often to hunt for food, sense vibrations on the ground and in the surrounding air to detect movement. Those who don’t go out at night but stay on their webs also sense tiny vibrations on their webs to detect movement. When they detect vibrations, that’s the only time they move to go out and check. It’s a sign to them of (possibly) food. It’s like when your doorbell rings — it might be the pizza delivery guy!

Hairy legs.

Most spiders sense vibrations both on the ground and in the air through fine microscopic hairs on their legs. Their hairy legs act as both their eyes and ears, especially at night. The hairs (or trichobothria) on their legs react to intensity of vibrations and gives the spider an idea of what the moving object might be. Spiders might not be able to see clearly, but their hairy legs can tell that a winged creature (bird or flying insect) is coming, through the changes in the surrounding air. Also, spiders use their hairy legs to smell. They also use their sense of smell to help them navigate in the dark, and detect prey or predator, A spider that shaves her legs is a deaf and blind spider!

hairy legs

Spiders’ eyes.

Most spiders can see during the day, albeit some need eyeglasses. But spiders’ eyes are not arranged in the same way for all spiders. It’s very fascinating to look at pictures of different species of spiders to see how their eyes line up. Some have four on top and four on the bottom of their face (e.g. Theridiidae, or cobweb spider; and Dictynidae, or mesh web spider). Some have six in front and one on either side of its head (e.g. Philodromidae, or crab spider). There is a species of spider who even has a pair of eyes near the back of its head (e.g. Oxyopidae, or lynx spider). And there are spiders who have two big eyes in front (e.g. Salticidae, or jumping spider) and two or four underneath (e.g. Lycosidae, or wolf spider), plus one on each side of its head. But their eyes are fixed, they can’t move their eyeballs or roll their eyes. So if you force a spider to agree to something it doesn’t like — it can’t roll its eyes!

eight eyes

Night hunters.

Spiders, e.g. wolf spiders, who have two big eyes in front of their faces, see more clearly than the others. These are daylight hunters. They are also great night time hunters. These spiders use their big eyes to focus on their prey. They also have two to four eyes underneath the two big eyes to give them an idea how far the prey is. In the case of these jumping spiders, knowing how far its prey is, is important for precision. It needs to visually measure how far it needs to jump to get to the prey. Slam dunk! Their big eyes are also useful to them in the dark of night.

spider eyes

Night vision.

Their big eyes also see in the dark. They adjust to low levels of light and are therefore good night hunters. Their eyes are lined with a tissue (tapetum lucidum) that reflects light. This is how they see in the dark. The tapetum reflects whatever light is gathered by the eye back to the retina to give it night vision. It boomerangs light back to the image perceived by the retina, like a secondary spotlight producing a clearer image. Cats, dogs, and many other night prowlers, like frogs and bats, have tapeta (plural of tapetum) in their eyes. If you shine a flashlight or if the headlight of your car hits a cat’s eyes, you’ll see it reflect back to you, in green, or red, or yellow. Try to shine a flashlight on your garden, do you see tiny reflections of green light returning to you? They’re probably wolf spiders — the night hunters.

Ogre-eyes.

There is a family of spiders (e.g. Deinopidae) that developed a pair of huge eyes for extreme night vision. Its name deinopidae is derived from the Greek word meaning ‘fearful appearance’. Because of their huge over-sized eyes they have been called the ogre-eyed spider. They really look ugly. Deinopidae have the largest pair of eyes and the most powerful night vision in the spider world. Their night vision is 1,000 times more powerful than human eyes. Also, they’re more powerful than cats’ or owls’ eyes. And their eyes glow in the dark.

ogre eyes

The light-sensitive membrane that powers their night vision dissolves and disappears every morning. And every night for two hours it produces a new membrane to replace it. Then it goes hunting for prey. It’s the Deinopidae’s daily life.

Net- casting.

Deinopidae are net-casting spiders. This means, they cast nets in order to catch their prey. They’re like fishermen who cast their net into the sea to catch fish. Only in this case, its a spider net. The net is woven from the same thread that spider webs are made. But they are thicker (10x) and naturally harder to break than the thin spider web. When the net is finally finished and ready for use, the deinopidae puts bait on the ground and hangs itself above the area holding the four corners of the net with four of its legs — ready to fall on its prey. Once an insect or a bug feeds on the bait, the deinopidae quickly falls on it and catches it with its net. It then wraps it all around with the net and injects its prey with venom and digestive enzymes. This all happens in the dark!

net casting

The blind spider.

Then there’s the blind spider. This spider (Sinopoda scurion) has no eyes at all. Absolutely no eyes! They live most of their lives in dark caves and lightless places. “Who needs eyes?!” they say. They have mastered the art of motion detection, with enhanced sensors for vibrations on the ground and in the air, and a very keen sense of smell. Another rare species of this eyeless spider is the Braken Bat Cave Meshweaver (Cicurina venii). It’s so rare it was last spotted in the 1980s.

The controversial rare spider.

The Braken Bat Cave Meshweaver hit the news channels in 2012 when a huge $15M underpass construction project in San Antonio, Texas, was stopped temporarily because they were building it on top of the spider’s home. Poor blind spider would have lost its home. But thanks to caring humans (biologists and conservationists) they were able to save the helpless spider. It was only the second time in history that this spider was seen by human eyes, after 1980.

blind spider

Seeing ultraviolet (UV) light.

Spiders generally see only two color wavelengths, viz. green and UV (ultraviolet). Humans see three, viz., red, green, and blue. You’ve probably seen it before, a sticker on your new color TV with the letters RGB (red, green, and blue). This means that your TV can mix these three color wavelengths to produce all shades of color, including white and black. Colors that the human eye normally sees. Unless you are color blind. And spiders are generally color blind. But they see UV light. Humans can’t.

Some species of spiders depend on UV light for survival. They make use of UV light in their mating rituals. This guarantees that they will reproduce more of their kind. The jumping spider, Consmophasis umbratica, uses UV light in their mating rituals. And both the male and female show physiological responses to the UV glow that they show each other. They get excited! But when scientists used UV blocking light during their mating rituals, both male and female C.umbratica showed no interest in each other. Talk about a wet blanket! It’s complicated.

Night life.

Night life has become a habit of spiders. One of the main reasons for this behavior is to avoid being seen. They are such socially awkward creatures. What kind of furry creature with eight arching legs, eight dark eyes (two sometimes bulging), and hanging fangs would want to be seen in public during the day?! Funny, no? But more than that, spiders avoid daytime predators, like birds and cats. Hunters like jumping spiders and wolf spiders are more intrepid and dare do their hunting during the day. It’s a risk they’re willing to take, for the thrill of the hunt and the prize. But most spiders are timid and couldn’t imagine being hunted down by predators, so they do most of their crawling and hunting at night. Besides, they don’t have the best eyesight, they argue. And they’ve developed improved sensors and a keen sense of smell to support their nocturnal hunting and feeding habits.

tarantula

For most spiders, it’s a matter of survival.

reunion sa cam sur

nagpunta kami ni jane, kamakailan, sa bicol; sa baao, cam sur, sa hometown nya. dinalaw namin si ma’lydz, nanay nya, biyenan ko. matagal-tagal na rin kasing hindi nakadalaw si jane sa nanay niya.

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rosalie, ma’lydz, at jane sa harap ng bahay ni ma’lydz

tumira kami sa kapatid ni jane, si rosalie, at ang bana nyang si emil, kasama nang apat na anak nila, at ang shitzu na si twinkle.

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shulamite, rosalie, jane, hannah, juris (& twinkle), dondon, emil sa may garahe

agad ipinakuha ni emil ang pina-alagaan nyang kambing. maya-maya eto na si ronil pasan-pasan ang kambing sa balikat nya.

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si rassel at si ronil (may pasan ng kambing)

sana daw kakaibang luto ng kambing ang gawin ko. sabi ko “curry” pero mukhang di sila masyadong excited dun.

nag-adobong kambing si emil. sya na rin ang nagluto ng papaitan. yung dapat lulutuin kong “curry” ay ginawa kong mestizong kaldereta — kalderetang ginataan na may kaunting curry powder.

datapwat ang naibigan ng lahat ay ang inihaw na ribs ng kambing.

 

napakasimple ng pamumuhay dito. napakabagal ng oras. ang tahimik ng gabi.

napakagalang din ng mga bata. naupo ako sandali sa upuang kawayan sa harapan ng tindahan, isang umaga.

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ako at si doglas (di nya tunay na pangalan)

lahat ng batang may bibilhin sa tindahan ay lalapit muna sa kin at isasahod ang kamay upang magmano — kahit hindi nila ako kakilala.

pinuntahan namin ang hipag ni jane, si len, asawa ng kapatid nyang si desiler na nasa brunei. tiga-albay sila. at dahil tiga-albay sila ay pumasyal muna kami sa kagsawa ruins para sulyapan ang daragang magayon.

“magustuhan ka kaya ng daragang mayon,” sabi ni jane, “magpapakita kaya sayo?”

nagpakita naman. at lubhang napakaganda at napaka-majestic ng daragang magayon — ang mayon!

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masaya akong lumisan sa kagsawa. nagpakita sa kin ang daragang magayon.

nagpunta kami kina len pagkagaling ng kagsawa. pinagluto nya kami ng inihaw na bangus, sinigang na baboy, at fried chicken. may dessert din na fruit salad. pinauwian ni len si jane ng ilang tanim nyang orchids, at ako naman ay pinauwian nya ng kampit.

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si len (dulo, kanan, naka-pink), si drenz (hawak ni len, at si drex (naka-dilaw na t-shirt)

kinagabihan ay pumasyal naman kami kina jake abad, si jung-jung na bunsong kapatid ni jane.

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usapang barangay IRA: si jane, si vangie (misis ni jung), at si jung a.k.a. jake abad.

si jung ay isang radio commentator ng station ng RPN, Nabua. at si vangie naman ay sec ni kap sa san vicente. naglabas si jung ng kaunting inumin (johnny wong-wong) matapos ang napakasarap na hapunan ng laing at sinanglay na tilapia.

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L to R: jung a.k.a. jake abad, me, emil

naka-tatlo o apat na “for the road” (tagay bago bumyahe pauwi) kami, bago tuluyang nag walk-out si rosalie. nun kami nagtapos… at umuwi.

pinagluto ko sina rosalie at emil ng specialty ko na pata tim nung linggo ng tanghali.

ipinag-ani kami ni emil ng isang buwig ng saging na saba mula sa mga tanim nya sa likod bakuran. pinauwian ako ni rosalie ng paborito kong tinuktok. dinagdagan naman ito ni jung ng saging bicol (kakaiba ito at napakatamis), kamote, guyabano, karagdagang tinuktok (pinangat), at ug-og (kamansi). ibinigay din sa ‘kin ni rosalie ang isang sangkalan na mahogany. ikinahon ni rosalie lahat nito bago kami umuwi.

kinagabihan ng linggo, hinatid kami ni emil at rosalie sa abangan ng bus sa plaza ng baao. pauwi na kami.

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inaabangan ang raymond bus sa tabing karsada malapit sa plaza ng baao

napakasayang reunion lalo na’t ang magkakapatid at magulang (ina) ay magkakasundo, sa kabila nang magkakalayo.

tiyak, babalik ako. 👌

 

good good friday

this year’s good friday was good, ergo — good good friday. it was my middle daughter’s (jikki) 27th birthday. and she’d decided to visit her lola (my mom) at loyola memorial park, marikina for her birthday.

i love her for thinking outside herself to visit her lola on her special day. my family has had many plans to visit, that had often ended up nowhere. this time it was a sure thing.

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my mom’s grave has been neglected. mea culpa. i plead guilty on that charge. and this day made me realize how important it is for one’s grave to be visited every so often, even when you’ve been long absent from the body.

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the lapida, after the surface was cleaned with a wet cloth

the lapida was dirty and soiled when we arrived, i had to rub off the smudge covering some of the lettering with the soles of my shoe.

a bit later, the caretaker of the grave beside my mom’s (my aunt’s and grandparents’ graves) came over and offered to clean and paint my mom’s lapida for P500. we agreed.

 

the caretaker’s name is danilo bandojo, a.k.a. danny bungal. there were two other caretakers named danny at loyola. one, danny bungal said, goes by ‘danny kalbo’.

danny bungal is 54 y.o. and has been taking care of my grandparents’ and aunt’s graves over the years now. he lives in antipolo and bikes two hours a day to and from work.

i asked him how much to plant grass, i particularly asked for carabao grass. “500 po,” he said. agreed.

“magkano mag-maintain?” i asked.

“150 a month po,” he said.

agreed. that is cheaper than a triple latte at starbucks! i negotiated an end of the month payment. he agreed.

i haggled for P450 for the cleaning and painting because the P500 he asked for included the purchase of spray paint. but he just borrowed paint, because stores were closed on good friday. he agreed.

for ka danny’s payment, i asked my daughters to pitch in any voluntary amount for the P450, to remind them of the thought of caring to spend a little, to show your love.

 

the lapida was a lovely sight after the cleaning and painting job. come first of may, we will send P500 to ka danny via cebuana lhuillier to plant carabao grass on my mom’s lot. thereafter, P150 every end of the month to maintain it by cleaning and watering the grass.

since we were already there at loyola memorial, jane also took the opportunity to offer flowers to his beloved uncle, ben f. rodriguez, and his wife. uncle ben took care of jane’s college schooling, and she lived with his family while she was in college.

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another person so dear to my heart was also laid to rest at loyola — jojo abagon, my cousin. we found her lot, and also offered flowers.

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the visit to loyola memorial park was a time to revisit cherished memories. the visit to loyola memorial park was a time to prepare myself for what was certainly to come in the future — my own eternal resting.

my family had lunch together and began our weekend stay-cation after lunch when we checked in for a 3D2N stay in a condo in the middle of metromanila.

jikki’s birthday was a good good friday!

 

 

eliz and CV

saturday was antithesis: in the morning, we were invited to a birthday breakfast buffet; in the afternoon, we went to a wake.  the birthday, was the 60th birthday celebration of a dear christian friend, eliz ‘maling’ francisco: the wake, the wake of an uncle, dr. cesar vicente san pedro, 87, who died of liver cancer.

there are no ironies — if ever there were — in birthdays.  in deaths there often are.  one of the ironies in deaths is that a death in the family becomes the occasion of happy reunions between siblings, cousins, relatives, and friends who haven’t seen each other in ages.  a death in the family brings us together, and the tragedy of death becomes a comedy of reunions.  an irony.  an irony on a tragedy…

maling is special.  she is one of a few.  she hosted the birthday breakfast buffet largely for her churchmates and us fellow christians (long-time friends) from all over (100-120 persons) — a huge blow-out!  she wanted to celebrate her 60th birthday with people closest to her heart.  the lady loves the Lord, and drives a silver jaguar.

 

at the wake of my uncle, it was a noisy reunion of cousins and close uncles and aunts.  noisy, filled with laughter and animated story-telling.  an irony on a tragedy…

i met CV, a 2nd cousin (son of my mother’s 1st cousin, the departed), the youngest.  i realized that for the past 30 odd years i have never talked to him — not a word — and not even exchanged a handshake greeting in countless clan reunions we’ve seen each other at.  yesterday was our first warm handshake, when i expressed my condolences to him upon our arriving at the wake…

“CV…” i said, “does that stand for cesar vicente, after your dad, cesar, and grand-dad, vicente?”
“his dad’s name is also cesar vicente,” my eldest brother rolly said.
“no, my name is cesar vincent,” CV said.
“ahh, tweaked,” i said…

CV, i learned, was a chef.  a would-have-been doctor like his dad and elder brother, paul, but chose another path — culinary arts.  he’s now the head chef at parq vancouver.  i asked him how he cooks scrambled eggs — gordon ramsey or anthony bourdain — to break the ice.  i said i didn’t like gordon ramsey’s scrambled eggs because they were “masyadong malasado” (too runny).  from then on, it was talk about chinese cuisine — herbs and spices, star anise, cooking wine, chicken powder, soup stock made from chicken, pork, and veal, century eggs mashed in congeee; pho, wansoy; bibimbop, kimchi — asian cuisine — after the ice breaker…

when it was time to go, i bade my cousins, uncle, and aunts goodbye.  i shook CV’s hand.

“at long last,” i said.
“oo nga,” he said.