Phaeacius
Encyclopedia
Phaeacius is a spider
genus of the family Salticidae (jumping spider
s), found in sub-tropical China
and between India
and the Malay Peninsula
, including Sri Lanka
, Sumatra
and the Philippines
. Although other spiders can jump, salticids including Phaeacius have significantly better vision than other spiders, and their main eyes are more acute in daylight than a cat
's and 10 times more acute than a dragonfly
's. The main eyes focus accurately on an object at distances from approximately 2 centimetre (0.78740157480315 in) to infinity, and in practice can see up to about 75 centimetres (29.5 in).
While most jumping spiders are active hunters, Phaeacius is unusually sedentary, generally resting in its unusual flattened pose for hours or days on logs, pieces of wood or any other solid surface, where it is very well camouflage
d. Its preferred prey is moth
s and other insect
s, and jumping spiders. Insects can usually move around an inactive Phaeacius, or even over its body, but if the insect moves between the spider's first pair of legs, Phaeacius lunges extremely quickly to bite the prey. Sometimes Phaeacius takes a more active approach, especially if without prey for a week or more. Phaeacius does not enter webs voluntary, and moves away if it touches one accidentally. It can bite through the threads and pull strongly with its legs, but cannot escape from very sticky webs.
The closest relatives of Phaeacius are in the genus
Holcolaetis
, and the next closest genera are Portia and Spartaeus
.
are fused into only two tagmata
, the cephalothorax
and abdomen
. Jumping spiders have a distinctive rectangular carapace
. All spiders' abdomens bear appendages that have been modified into spinnerets that extrude silk
from up to six types of silk glands within their abdomen. The cephalothorax and abdomen are joined by a small, cylindrical pedicel
, which allows the abdomen to move while spinning silk
. While most jumping spiders do not build webs to catch prey, they use silk
for other purposes, including moult
ing and laying eggs.
The whole body of Phaeacius is 7.5 to 11.5 mm (0.295275590551181 to 0.452755905511811 in) long, and notably flattened, including the carapace
, while the carapaces of some other groups are raised. The cepholothorax of Phaeacius′ is relatively long, and the highest point is a little behind the last pair of eyes. Phaeacius is very well camouflage
d; for example, P. malayensis has a body with dull grey and brown markings that resemble the surface of tree trunks in the rainforest.
Jumping spiders generally have large forelegs and short, powerful back legs, and can leap up to 50 times their own length by powerfully extending the third or fourth pairs of legs. In spiders and other chelicerates, there is only one pair of appendage
s before the mouth, and in spiders these are modified into fangs that inject poison into the prey. Behind the mouth is a pair of pedipalp
s ("palps" for short), and those of male spiders are quite large and are used for displaying and mating.
are almost as large as the other secondary eyes. Although other spiders can jump, salticids including Phaeacius have significantly better vision than other spiders, and their main eyes are more acute in daylight than a cat
's and 10 times more acute than a dragonfly
's. The main eyes focus accurately on an object at distances from approximately 2 centimetre (0.78740157480315 in) to infinity, and in practice can see up to about 75 centimetres (29.5 in).
Spiders, like other arthropod
s, have sensors, often modified seta
e (bristles), protruding through their cuticle
("skin") for smell, taste, touch and vibration. Unlike insect
s, spiders and other chelicerates do not have antennae
.
pressed against the surface, the hindmost legs upwards and the other legs downwards, and its markings and flattened body make it easily hidden
against the bark of a tree trunk. Its habit of walking with its body and legs flattened against a surface helps Phaeacius to be unobtrusive.
do not leap on prey, but lunge from about half the predator's body length away.
Phaeacius is unusually sedentary for a jumping spider, generally resting in the flattened pose for hours or days on logs, pieces of wood or any other solid surface, and captures particular types of prey more often when the predator matches this background. Insects can usually move around an inactive Phaeacius, or even over its body or legs. However, if the insect moves between the spider's first pair of legs, Phaeacius lunges extremely quickly, driving its body upward 2 to 3 mm (0.078740157480315 to 0.118110236220472 in) and forward about half the length of its body. The lunge ends with the spider's fangs in the prey and often with the foremost two pairs of legs forming a basket over the prey. When the prey stops struggling, Phaeacius resumes the flattened pose and then feeds.
However, Phaeacius can adopt other, more active approaches, with different gaits for each. If an insect remains almost stationary while Phaeacius is in the flattened pose and facing the insect, the spider may step slowly forward to its prey, rocking and keeping its flattened pose. To rock, Phaeacius moves about half a body length forward then, without pausing, smoothly back almost to the previous position. It performs about 10 cycles of those movements, progressing by 1 to 2 mm (0.0393700787401575 to 0.078740157480315 in) per cycle, and then rests. This rocking motion may disguise Phaeacius as shadows on the tree trunk. The insect occasionally keeps stationary until Phaeacius reaches within about half a body length and then lunges.
When hunting other jumping spiders and when the background matches its coloration, Phaeacius uses "insinuation", in which it waits, sometimes up to an hour, while a jumping spider moves around nearby, and then Phaeacius suddenly turns up to 180° toward the prey and then resumes the flattened pose. Phaeacius then moves a few millimetres toward the prey and resumes the flattened pose. If the prey moves away, Phaeacius continues the insinuation manoeuvre, but if the prey moves toward it, Phaeacius lunges. Other jumping spiders show no awareness of a flattened Phaeacius on a matching background, and apparently survive by luck. When the background does not matches Phaeacius′ coloration, other jumping spiders recognise Phaeacius as a threat.
Sometimes, especially if without prey for a week or more, Phaeacius may approach insects faster, from 50 to 100 mm (2 to 3.9 in) away, and if necessary turning round to face the prey. Often Phaeacius then adopts the flattened pose after the turn, but sometimes it walks faster than usual and, without pausing, lunges from about half its body length.
In a test on a background matching its own coloration, Phaeacius was most successful against other salticids and then against moths, and was also successful against flies and hunting spiders. On a non-matching background, Phaeacius was most successful against moths.
Phaeacius does not try to eat other spiders' eggs, does not enter webs voluntarily, and moves away if it touches one accidentally. It can bite through the threads and pull strongly with its legs, but cannot escape from very sticky webs. This behaviour is quite different from that of its close relative, Portia, which hunts actively and can enter any type of web to catch spiders and their eggs.
When disturbed, some jumping spiders usually run away quickly and leap if chased. Phaeacius stays in its flattened posture unless harassed, when it runs quickly for about 100 to 300 mm (3.9 to 11.8 in) and then adopts the flattened posture, and finally walks away about 10 minutes later.
, male spiders spin a small web and ejaculate on to it, and then store the semen
in reservoirs on his pedipalp
s, which are larger than those of females. Phaeacius spins a flimsy silken
, horizontal or vertical platform, about twice the spider's length in diameter, to moult
and lay eggs, but not at other times. After the moult, Phaeacius leaves the discarded exuvia
hanging from the platform. A female's egg sac is placed in a shallow cavity on the surface of a log.
of the Salticidae family (jumping spider
s). Phaeacius is in the subfamily Spartaeinae
, which is thought to be primitive. Molecular phylogeny
, a technique that compares the DNA
of organisms to reconstruct the tree of life, indicates that Phaeacius is a member of the clade
Spartaeinae, that Spartaeinae is basal (quite similar to the ancestors of all jumping spiders), and that Phaeacius′s closest relative is the genus Holcolaetis
, and that the next closest are Portia and Spartaeus
.
The genus is found in sub-tropical China and between India and Malaya
, including Sri Lanka
, Sumatra
and the Philippines
. The genus was first described by Eugène Simon
in 1900, and includes 12 formally described species – P. alabangensis, P. biramosus, P. canalis , P. fimbriatus, P. lancearius, P. leytensis, P. mainitensis, P. malayensis , P. saxicola, P. wanlessi , P. yixin and P. yunnanensis. The type species is P. fimbriatus.
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
genus of the family Salticidae (jumping spider
Jumping spider
The jumping spider family contains more than 500 described genera and about 5,000 described species, making it the largest family of spiders with about 13% of all species. Jumping spiders have some of the best vision among invertebrates and use it in courtship, hunting and navigation...
s), found in sub-tropical China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
and between India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
and the Malay Peninsula
Malay Peninsula
The Malay Peninsula or Thai-Malay Peninsula is a peninsula in Southeast Asia. The land mass runs approximately north-south and, at its terminus, is the southern-most point of the Asian mainland...
, including Sri Lanka
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...
, Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
and the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
. Although other spiders can jump, salticids including Phaeacius have significantly better vision than other spiders, and their main eyes are more acute in daylight than a cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
's and 10 times more acute than a dragonfly
Dragonfly
A dragonfly is a winged insect belonging to the order Odonata, the suborder Epiprocta or, in the strict sense, the infraorder Anisoptera . It is characterized by large multifaceted eyes, two pairs of strong transparent wings, and an elongated body...
's. The main eyes focus accurately on an object at distances from approximately 2 centimetre (0.78740157480315 in) to infinity, and in practice can see up to about 75 centimetres (29.5 in).
While most jumping spiders are active hunters, Phaeacius is unusually sedentary, generally resting in its unusual flattened pose for hours or days on logs, pieces of wood or any other solid surface, where it is very well camouflage
Camouflage
Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
d. Its preferred prey is moth
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
s and other insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, and jumping spiders. Insects can usually move around an inactive Phaeacius, or even over its body, but if the insect moves between the spider's first pair of legs, Phaeacius lunges extremely quickly to bite the prey. Sometimes Phaeacius takes a more active approach, especially if without prey for a week or more. Phaeacius does not enter webs voluntary, and moves away if it touches one accidentally. It can bite through the threads and pull strongly with its legs, but cannot escape from very sticky webs.
The closest relatives of Phaeacius are in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Holcolaetis
Holcolaetis
Holcolaetis is a genus of the spider family Salticidae .Like Euryattus and Thiania bhamoensis, these spiders build a flat, densely woven egg sac that is not contiguous with the silk of the nest...
, and the next closest genera are Portia and Spartaeus
Spartaeus
Spartaeus is a spider genus of the Salticidae family .The genus was renamed from Boethus in 1984 because the name was found to be preoccupied.-Species:* Spartaeus abramovi Logunov & Azarkina, 2008 — Vietnam...
.
Body structure
Spiders are chelicerates, which differ from other arthropods in that the usual body segmentsSegmentation (biology)
Segmentation in biology refers to either a type of gastrointestinal motility or the division of some animal and plant body plans into a series of repetitive segments. This article will focus on the segmentation of animal body plans, specifically using the examples of the phyla Arthropoda,...
are fused into only two tagmata
Tagma (biology)
In invertebrate biology, a tagma is a specialized grouping of arthropod segments, such as the head, the thorax, and the abdomen with a common function. The segments of a tagma may be either fused or moveable.-Tagmata:...
, the cephalothorax
Cephalothorax
The cephalothorax is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. The word cephalothorax is derived from the Greek words for head and thorax...
and abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
. Jumping spiders have a distinctive rectangular carapace
Carapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
. All spiders' abdomens bear appendages that have been modified into spinnerets that extrude silk
Spider silk
Spider silk is a protein fiber spun by spiders. Spiders use their silk to make webs or other structures, which function as nets to catch other animals, or as nests or cocoons for protection for their offspring...
from up to six types of silk glands within their abdomen. The cephalothorax and abdomen are joined by a small, cylindrical pedicel
Pedicel (spider)
The pedicel of a spider is a small, flexible cylinder that joins the cephalothorax and abdomen. This helps the spider to spin silk without moving the cephalothorax....
, which allows the abdomen to move while spinning silk
Silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...
. While most jumping spiders do not build webs to catch prey, they use silk
Spider silk
Spider silk is a protein fiber spun by spiders. Spiders use their silk to make webs or other structures, which function as nets to catch other animals, or as nests or cocoons for protection for their offspring...
for other purposes, including moult
Moult
In biology, moulting or molting , also known as sloughing, shedding, or for some species, ecdysis, is the manner in which an animal routinely casts off a part of its body , either at specific times of year, or at specific points in its life cycle.Moulting can involve the epidermis , pelage...
ing and laying eggs.
The whole body of Phaeacius is 7.5 to 11.5 mm (0.295275590551181 to 0.452755905511811 in) long, and notably flattened, including the carapace
Carapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
, while the carapaces of some other groups are raised. The cepholothorax of Phaeacius′ is relatively long, and the highest point is a little behind the last pair of eyes. Phaeacius is very well camouflage
Camouflage
Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
d; for example, P. malayensis has a body with dull grey and brown markings that resemble the surface of tree trunks in the rainforest.
Jumping spiders generally have large forelegs and short, powerful back legs, and can leap up to 50 times their own length by powerfully extending the third or fourth pairs of legs. In spiders and other chelicerates, there is only one pair of appendage
Appendage
In invertebrate biology, an appendage is an external body part, or natural prolongation, that protrudes from an organism's body . It is a general term that covers any of the homologous body parts that may extend from a body segment...
s before the mouth, and in spiders these are modified into fangs that inject poison into the prey. Behind the mouth is a pair of pedipalp
Pedipalp
Pedipalps , are the second pair of appendages of the prosoma in the subphylum Chelicerata. They are traditionally thought to be homologous with mandibles in Crustacea and insects, although more recent studies Pedipalps (commonly shortened to palps or palpi), are the second pair of appendages of the...
s ("palps" for short), and those of male spiders are quite large and are used for displaying and mating.
Senses
Jumping spiders have eight eyes, the two large ones in the centre-and-front position (the anterior-median eyes, also called "principal eyes") providing acute vision and housed in tubes in the head. The other six are secondary eyes, positioned along the sides of the carapace and acting mainly as movement detectors. While the middle pair of secondary eyes in most jumping spiders are small, those of Phaeacius and other members of the sub-family SpartaeinaeSpartaeinae
The Spartaeinae are a subfamily of the spider family Salticidae . It was established by Fred R. Wanless in 1984 to include the groups Boetheae, Cocaleae, Lineae, Codeteae and Cyrbeae, which in turn were defined by Eugène Simon....
are almost as large as the other secondary eyes. Although other spiders can jump, salticids including Phaeacius have significantly better vision than other spiders, and their main eyes are more acute in daylight than a cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
's and 10 times more acute than a dragonfly
Dragonfly
A dragonfly is a winged insect belonging to the order Odonata, the suborder Epiprocta or, in the strict sense, the infraorder Anisoptera . It is characterized by large multifaceted eyes, two pairs of strong transparent wings, and an elongated body...
's. The main eyes focus accurately on an object at distances from approximately 2 centimetre (0.78740157480315 in) to infinity, and in practice can see up to about 75 centimetres (29.5 in).
Spiders, like other arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s, have sensors, often modified seta
Seta
Seta is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms.-Animal setae:In zoology, most "setae" occur in invertebrates....
e (bristles), protruding through their cuticle
Cuticle
A cuticle , or cuticula, is a term used for any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticles" are non-homologous; differing in their origin, structure, function, and chemical composition...
("skin") for smell, taste, touch and vibration. Unlike insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, spiders and other chelicerates do not have antennae
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
.
Movement and being undetected
While most jumping spiders walk quickly, in a stop-go gait and jumping over obstacles, the movements of Phaeacius are very unusual. Phaeacius usually uses a "flattened posture" head-down on a vertical surface, with the body, legs and palpsPedipalp
Pedipalps , are the second pair of appendages of the prosoma in the subphylum Chelicerata. They are traditionally thought to be homologous with mandibles in Crustacea and insects, although more recent studies Pedipalps (commonly shortened to palps or palpi), are the second pair of appendages of the...
pressed against the surface, the hindmost legs upwards and the other legs downwards, and its markings and flattened body make it easily hidden
Crypsis
In ecology, crypsis is the ability of an organism to avoid observation or detection by other organisms. It may be either a predation strategy or an antipredator adaptation, and methods include camouflage, nocturnality, subterranean lifestyle, transparency, and mimicry...
against the bark of a tree trunk. Its habit of walking with its body and legs flattened against a surface helps Phaeacius to be unobtrusive.
Feeding and defence
While almost all jumping spiders are predators, mostly preying on insects, on other spiders, and on other arthropods, Phaeacius does not use the usual hunting tactics. Most jumping spiders walk throughout the day, so that they maximise their chances of a catch, and jump on their prey and then bite it. Unlike most jumping spiders, Phaeacius and other spartaeinesSpartaeinae
The Spartaeinae are a subfamily of the spider family Salticidae . It was established by Fred R. Wanless in 1984 to include the groups Boetheae, Cocaleae, Lineae, Codeteae and Cyrbeae, which in turn were defined by Eugène Simon....
do not leap on prey, but lunge from about half the predator's body length away.
Phaeacius is unusually sedentary for a jumping spider, generally resting in the flattened pose for hours or days on logs, pieces of wood or any other solid surface, and captures particular types of prey more often when the predator matches this background. Insects can usually move around an inactive Phaeacius, or even over its body or legs. However, if the insect moves between the spider's first pair of legs, Phaeacius lunges extremely quickly, driving its body upward 2 to 3 mm (0.078740157480315 to 0.118110236220472 in) and forward about half the length of its body. The lunge ends with the spider's fangs in the prey and often with the foremost two pairs of legs forming a basket over the prey. When the prey stops struggling, Phaeacius resumes the flattened pose and then feeds.
However, Phaeacius can adopt other, more active approaches, with different gaits for each. If an insect remains almost stationary while Phaeacius is in the flattened pose and facing the insect, the spider may step slowly forward to its prey, rocking and keeping its flattened pose. To rock, Phaeacius moves about half a body length forward then, without pausing, smoothly back almost to the previous position. It performs about 10 cycles of those movements, progressing by 1 to 2 mm (0.0393700787401575 to 0.078740157480315 in) per cycle, and then rests. This rocking motion may disguise Phaeacius as shadows on the tree trunk. The insect occasionally keeps stationary until Phaeacius reaches within about half a body length and then lunges.
When hunting other jumping spiders and when the background matches its coloration, Phaeacius uses "insinuation", in which it waits, sometimes up to an hour, while a jumping spider moves around nearby, and then Phaeacius suddenly turns up to 180° toward the prey and then resumes the flattened pose. Phaeacius then moves a few millimetres toward the prey and resumes the flattened pose. If the prey moves away, Phaeacius continues the insinuation manoeuvre, but if the prey moves toward it, Phaeacius lunges. Other jumping spiders show no awareness of a flattened Phaeacius on a matching background, and apparently survive by luck. When the background does not matches Phaeacius′ coloration, other jumping spiders recognise Phaeacius as a threat.
Sometimes, especially if without prey for a week or more, Phaeacius may approach insects faster, from 50 to 100 mm (2 to 3.9 in) away, and if necessary turning round to face the prey. Often Phaeacius then adopts the flattened pose after the turn, but sometimes it walks faster than usual and, without pausing, lunges from about half its body length.
In a test on a background matching its own coloration, Phaeacius was most successful against other salticids and then against moths, and was also successful against flies and hunting spiders. On a non-matching background, Phaeacius was most successful against moths.
Phaeacius does not try to eat other spiders' eggs, does not enter webs voluntarily, and moves away if it touches one accidentally. It can bite through the threads and pull strongly with its legs, but cannot escape from very sticky webs. This behaviour is quite different from that of its close relative, Portia, which hunts actively and can enter any type of web to catch spiders and their eggs.
When disturbed, some jumping spiders usually run away quickly and leap if chased. Phaeacius stays in its flattened posture unless harassed, when it runs quickly for about 100 to 300 mm (3.9 to 11.8 in) and then adopts the flattened posture, and finally walks away about 10 minutes later.
Reproduction
Before courtshipCourtship
Courtship is the period in a couple's relationship which precedes their engagement and marriage, or establishment of an agreed relationship of a more enduring kind. In courtship, a couple get to know each other and decide if there will be an engagement or other such agreement...
, male spiders spin a small web and ejaculate on to it, and then store the semen
Semen
Semen is an organic fluid, also known as seminal fluid, that may contain spermatozoa. It is secreted by the gonads and other sexual organs of male or hermaphroditic animals and can fertilize female ova...
in reservoirs on his pedipalp
Pedipalp
Pedipalps , are the second pair of appendages of the prosoma in the subphylum Chelicerata. They are traditionally thought to be homologous with mandibles in Crustacea and insects, although more recent studies Pedipalps (commonly shortened to palps or palpi), are the second pair of appendages of the...
s, which are larger than those of females. Phaeacius spins a flimsy silken
Spider silk
Spider silk is a protein fiber spun by spiders. Spiders use their silk to make webs or other structures, which function as nets to catch other animals, or as nests or cocoons for protection for their offspring...
, horizontal or vertical platform, about twice the spider's length in diameter, to moult
Moult
In biology, moulting or molting , also known as sloughing, shedding, or for some species, ecdysis, is the manner in which an animal routinely casts off a part of its body , either at specific times of year, or at specific points in its life cycle.Moulting can involve the epidermis , pelage...
and lay eggs, but not at other times. After the moult, Phaeacius leaves the discarded exuvia
Exuvia
Exuviae is a term used in biology to describe the remains of an exoskeleton and related structures that are left after ecdysozoans have moulted...
hanging from the platform. A female's egg sac is placed in a shallow cavity on the surface of a log.
Taxonomy and distribution
Phaeacius is a spider genusGenus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of the Salticidae family (jumping spider
Jumping spider
The jumping spider family contains more than 500 described genera and about 5,000 described species, making it the largest family of spiders with about 13% of all species. Jumping spiders have some of the best vision among invertebrates and use it in courtship, hunting and navigation...
s). Phaeacius is in the subfamily Spartaeinae
Spartaeinae
The Spartaeinae are a subfamily of the spider family Salticidae . It was established by Fred R. Wanless in 1984 to include the groups Boetheae, Cocaleae, Lineae, Codeteae and Cyrbeae, which in turn were defined by Eugène Simon....
, which is thought to be primitive. Molecular phylogeny
Molecular phylogeny
Molecular phylogenetics is the analysis of hereditary molecular differences, mainly in DNA sequences, to gain information on an organism's evolutionary relationships. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree...
, a technique that compares the DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
of organisms to reconstruct the tree of life, indicates that Phaeacius is a member of the clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
Spartaeinae, that Spartaeinae is basal (quite similar to the ancestors of all jumping spiders), and that Phaeacius′s closest relative is the genus Holcolaetis
Holcolaetis
Holcolaetis is a genus of the spider family Salticidae .Like Euryattus and Thiania bhamoensis, these spiders build a flat, densely woven egg sac that is not contiguous with the silk of the nest...
, and that the next closest are Portia and Spartaeus
Spartaeus
Spartaeus is a spider genus of the Salticidae family .The genus was renamed from Boethus in 1984 because the name was found to be preoccupied.-Species:* Spartaeus abramovi Logunov & Azarkina, 2008 — Vietnam...
.
The genus is found in sub-tropical China and between India and Malaya
Malay Peninsula
The Malay Peninsula or Thai-Malay Peninsula is a peninsula in Southeast Asia. The land mass runs approximately north-south and, at its terminus, is the southern-most point of the Asian mainland...
, including Sri Lanka
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...
, Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
and the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
. The genus was first described by Eugène Simon
Eugène Simon
Eugène Simon was a French arachnologist. His many taxonomic contributions include categorizing and naming many spiders, as well as creating genera such as Anelosimus, Psellocoptus and Phlogius....
in 1900, and includes 12 formally described species – P. alabangensis, P. biramosus, P. canalis , P. fimbriatus, P. lancearius, P. leytensis, P. mainitensis, P. malayensis , P. saxicola, P. wanlessi , P. yixin and P. yunnanensis. The type species is P. fimbriatus.