Thoghut

     Thoghut adalah setiap yang disembah selain Alloh Subhanahu wa Ta’ala, ia rela dengan peribadatan yang dilakukan oleh penyembah atau pengikutnya, atau rela dengan keta’atan orang yang menta’atinya dalam hal maksiat kepada Alloh Subhanahu wa Ta’ala dan RasulNya.

Alloh Subhanahu wa Ta’ala mengutus para Rasul agar memerintahkan kaumnya menyembah kepada Alloh Subhanahu wa Ta’ala semata dan menjauhi segala bentuk thoghut. Alloh Subhanahu wa Ta’ala berfirman, yang artinya: “Dan sesungguhnya Kami telah mengutus Rasul pada tiap-tiap umat (untuk menyerukan), ‘Sembahlah Allah (semata), dan jauhilah thoghut itu’.” (QS: An-Nahl: 36)

Bentuk thoghut itu amat banyak, tetapi pemimpin mereka ada lima, yaitu:

Setan.
Thoghut ini selalu menyeru beribadah kepada selain Alloh Subhanahu wa Ta’ala. Dalil-nya adalah firman Alloh Subhanahu wa Ta’ala, yang artinya: “Bukankah Aku telah memerintahkan kepadamu hai Bani Adam supaya kamu tidak menyembah setan? Sesungguhnya setan itu adalah musuh yang nyata bagi kamu.” (QS: Yaasiin: 60)

Penguasa zhalim yang mengubah hukum-hukum Alloh Subhanahu wa Ta’ala.
Seperti peletak undang-undang yang tidak sejalan dengan Islam. Dalilnya adalah firman Alloh Subhanahu wa Ta’ala yang mengingkari orang-orang musyrik. Mereka membuat peraturan dan undang-undang yang tidak diridhai oleh Alloh Subhanahu wa Ta’ala. Alloh Subhanahu wa Ta’ala berfirman, yang artinya: “Apakah mereka mempunyai sembahan-sembahan selain Alloh yang mensyari’atkan untuk mereka agama yang tidak diizinkan Alloh?” (QS: Asy-Syuuraa: 21)

Hakim yang tidak memutuskan menurut apa yang diturunkan Alloh Subhanahu wa Ta’ala.
Jika ia mempercayai bahwa hukum-hukum yang diturunkan Alloh Subhanahu wa Ta’ala tidak sesuai lagi, atau dia membolehkan diberlakukannya hukum yang lain. Alloh Subhanahu wa Ta’ala berfirman, yang artinya: “Dan barangsiapa yang tidak memutuskan menurut apa yang diturunkan Allah, maka mereka itu adalah orang-orang yang kafir”. (QS: Al-Maa’idah: 44)

Orang yang mengaku mengetahui ilmu ghaib selain Alloh Subhanahu wa Ta’ala.
Dalam hal ini Allah Alloh Subhanahu wa Ta’ala berfirman, yang artinya: “Katakanlah, ‘Tidak ada seorang pun di langit dan di bumi yang mengetahui perkara yang ghaib, kecuali Alloh’.” (Qs: An-Naml: 65)

Seseorang atau sesuatu yang disembah dan diminta pertolongan oleh manusia selain Alloh Subhanahu wa Ta’ala, sedang ia rela dengan yang demikian.
Dalilnya adalah firman Alloh Subhanahu wa Ta’ala, yang artinya: “Dan barangsiapa di antara mereka mengatakan, ‘Sesungguhnya aku adalah Tuhan selain Alloh’. Maka orang itu Kami beri balasan dengan Jahannam, demikian Kami memberikan pembalasan kepada orang-orang zhalim.” (QS: Al-Anbiyaa’: 29)

Setiap mukmin wajib mengingkari thaghut sehingga ia menjadi seorang mukmin yang lurus. Alloh Subhanahu wa Ta’ala berfirman, yang artinya: “Karena itu, barangsiapa yang ingkar kepada thaghut dan beriman kepada Allah, maka sesungguhnya ia telah berpegang kepada buhul tali yang amat kuat yang tidak akan putus. Dan Alloh Maha Mendengar lagi Maha Mengetahui.” (QS: Al-Baqarah: 256)

Ayat ini merupakan dalil bahwa ibadah kepada Alloh Subhanahu wa Ta’ala sama sekali tidak bermanfa’at, kecuali dengan menjauhi beribadah kepada selain-Nya. Rasululloh ShallAllahu’alaihi wa Sallam menegaskan hal ini dalam sabdanya, yang artinya: “Barangsiapa mengucapkan, ‘Laa ilaaha illallah’, dan mengingkari apa yang disembah selain Alloh, maka haram atas harta dan darahnya”. (HR: Muslim)

(Sumber Rujukan: Al Firqotun Naajiyah, Syaikh Muhammad Jamil Zainu)n

Fish Respiration

RESPIRATION

In order to live, fish must extract oxygen from the water and transfer it to their bloodstream. This is done by gills, lungs, specialized chambers, or skin, any of which must be richly supplied with blood vessels in order to act as a respiratory organ. Extracting oxygen from water is more difficult and requires a greater expenditure of energy than does extracting oxygen from air. Water is a thousand times more dense (heavier per unit volume) than air, and at 20 deg C (68 deg F) it has 50 times more viscosity (resistance to flow) than air and contains only 3% as much oxygen as an equal volume of air. Fishes, therefore, have necessarily evolved very efficient systems for extracting oxygen from water; some fishes are able to extract as much as 80% of the oxygen contained in the water passing over the gills, whereas humans can extract only about 25% of the oxygen from the air taken into the lungs.

Gills are made efficient in a number of ways.
1) A large surface area for gaseous exchange means that more oxygen can enter the bloodstream over a given period of time. A single gill of a bony fish consists of a curved gill arch bearing a V-shaped double row of gill filaments. Each filament has many minute folds in its surface, giving it a sort of fuzzy appearance and increasing the amount of surface area along a given length of filament. Consequently, the surface area of the gills is commonly 10 to 60 times more than that of the whole body surface :
2) A short diffusion, or travel, distance for the oxygen increases the rate of oxygen entry into the blood. The blood traveling in the folds of the filaments is very close to the oxygen-containing water, being separated from it by a very thin membrane usually 1 to 3 microns (4/100,000 to 1/10,000 in) thick, and possibly less.
3) By using countercurrent circulation in the gill, the blood in the filament folds travels forward, in the opposite direction to the water flow, so that a constant imbalance is maintained between the lower amount of oxygen in the blood and the higher amount in the water, ensuring passage of oxygen to the blood. If the blood were to flow in the same direction as the water, oxygenated blood at the rear of the gills would be traveling with deoxygenated water and not only could not extract oxygen from the water but would even lose oxygen to it.
4) Gills have little physiological dead space. The folds of the filament are close enough together so that most of the water passing between them is involved in the gas-exchange process.
5) Water flows continuously in only one direction over the gills, as contrasted with the interrupted, two-way flow of air in and out of lungs of mammals.

Fish circulation

CIRCULATION

The blood of the fish serves, as does the blood of other vertebrates, to transport oxygen, nutrients, and wastes. The typical fish's circulation is a single circuit: heart-gills-body-heart. In contrast, mammals have two circuits: heart-lungs-heart and heart-body-heart. The fish heart proper is two-chambered, consisting of an upper atrium and a lower ventricle. Amphibians, basically, have a three-chambered heart, two atria and one ventricle; reptiles have a three- or four-chambered heart; and mammals and birds have a four-chambered heart consisting of two atria and two ventricles. The fish heart, however, has two accessory chambers, and all four chambers are contained within a single pericardial sac. One accessory chamber is the thin-walled sinus venosus, which collects blood and leads into the atrium; the other accessory chamber is the conus arteriosus, an enlargement of the main artery leading out of the ventricle. In some fishes, such as sharks, the conus arteriosus is muscular and pumps blood in the manner of the ventricle.

Fish Anatomy

ANATOMY

The living species of fish are usually divided into three classes: the Agnatha, the jawless fishes, comprising the hagfishes and lampreys; the Chondrichthyes, the cartilaginous-skeleton fishes, such as sharks and rays; and the Osteichthyes, the bony-skeleton fishes, comprising all other living fishes. The skeletons of these three groups vary in fundamental ways. In the hagfishes and lampreys the backbone is basically a notochord, a rodlike structure composed of unique notochordal tissue. In sharks and rays the notochord is surrounded and constricted by spaced rings of cartilage, the vertebrae, to form a backbone. The remainder of the skeleton is also cartilaginous, not bony, but in many forms the cartilage is partly calcified, and thereby hardened, by the addition of calcareous salts. In primitive bony fishes, such as the sturgeon, the vertebrae spaced along the notochord are still largely cartilaginous, but in most advanced bony fishes the vertebrae are bony and are united to form the backbone, and the notochord is no longer present.

Some fishes, such as lampreys, lack ribs; others have either a single or a double pair of ribs attached to each trunk vertebra. Among the higher bony fishes there also may be small, riblike intermuscular bones, which often render such fish difficult to eat.

The body appendages of fish are of two kinds, cirrhi and fins. Cirrhi are flaps of flesh that may appear on any part of the body; they often serve as camouflage. Fins are either median or paired. Median fins are situated along the centerline of the body, at the top, the bottom, and the end. The top, or dorsal, fin may consist of one to several fins, one behind the other, and may include a fleshy fin, called the adipose fin, near the tail. The bottom, or anal, fin is located on the belly behind the vent, or anus. The end fin is called the tail, or caudal, fin.

The dorsal and anal fins may be supported by cartilaginous rods, as in the lampreys, by cartilaginous rods and horny rays, as in sharks, by horny rays, as in the spiny-finned fishes, or by bony rays (derived from scales) in the soft-rayed fishes. The tail fin may be protocercal, the body continuing straight back as a middle support between the upper and lower lobes of the tail; heterocercal, with the end of the body turning up and continuing to the tip of the upper lobe; or homocercal, in which the last few vertebrae are fused and joined with other bony elements (hypurals) to support the tail-fin rays. A modification of the heterocercal tail so as to resemble the protocercal type is called diphycercal.

The paired fins correspond to the arms and legs of land vertebrates. The pectoral fins are situated at the front of the body behind the gill openings and generally function to provide maneuverability, but may be highly modified to fulfill other functions. The simplest internal support for the pectoral fins occurs in the sharks, where a U-shaped cartilaginous skeletal structure, called the pectoral girdle, joins and helps support the two pectoral fins. In the higher bony fishes the pectoral girdle is composed of bone and is more complex in structure. The pelvic fins, also called the ventral fins, are located along the bottom of the body but vary considerably in their placement. They may be located in the middle of the belly, as in salmon; below the pectorals, as in the largemouth bass; or in front of the pectorals, as in cods. Pelvic fins also serve as maneuvering structures and also may be modified to serve other uses. The supporting pelvic girdle is lacking in many bony fishes; in most fishes in which the pelvic girdle is present it is represented by a single skeletal element on each side of the body.

The scales of fish are colorless; a fish's coloring arises from structures beneath or closely associated with the scales. Not all species of fishes have scales, or the scales may be so small as to make the fish appear scaleless. Scales also may be present only on small areas of the body. The arrangement of scales may be imbricate (overlapping like the shingles on a roof) or mosaic (fitting closely together or just minutely separated).

Four basic scale types can be distinguished on the basis of structure. Placoid scales, also called dermal denticles, are found on sharks and rays and are toothlike in structure. Indeed, modified and enlarged placoid scales have become the teeth of sharks. The placoid scale consists of an upper layer of enamellike substance called vitrodentine, a lower layer of dentine, a pulp cavity, and a disklike basal plate embedded in the skin. Placoid scales do not increase in size as do the scales of bony fishes, and new scales must be added as a shark grows.

Cosmoid scales are found on the primitive coelacanth. They also occur on lungfishes, but in a highly modified, single-layered form. The cosmoid scale of the coelacanth is a four-layered bony scale. The upper layer is enamellike vitrodentine; the second layer is a hard, dentinelike substance called cosmine; the third layer is spongy bone, and the lowest layer is dense bone.

Ganoid scales, as found on gars, are typically squarish (rhombic) in shape and consist of a single bony layer, a layer of cosmine, and a covering of a very hard enamellike substance called ganoin.

Leptoid scales are believed to have been derived from ganoid scales by the loss of the ganoin layer; they consist of a single layer of bone. Leptoid scales are found on the higher bony fishes and occur in two forms: cycloid (circular) and ctenoid (toothed), the latter bearing tiny comblike projections. The single-layered cosmoid scale of lungfishes also may be classified as leptoid, although of a different derivation.